Answer:
Hydrogen spectrum
Explanation:
Balmer series - Observed in the visible region
Brackett series - Observed in the infrared region
Paschen series - Observed in the infrared region
Lyman series - Observe in the Ultraviolet region.
There are four sets of lines seen in the hydrogen emission spectra are Lyman series in the UV region, Balmer in the visible region and bracket and paschen in the IR region.
What is emission spectra?Emission spectrum is set of radiations emitted by an atom in the order of increasing frequency or decreasing wavelengths. Electrons in atoms transit between various energy levels.
Electrons excites from the lower energy level to the higher energy level by the absorption of light and return back to the ground state by emitting a complementary light.
The lyman series in the hydrogen emission spectrum is starting from the energy level n= 1. It is seen in the UV-region. Balmer series is found in visible region and their n value starts from n = 2.
Similarly Bracket starts from n= 3 and paschen series starts from n= 4. Both are overlapping lines together and they are seen in IR region.
To find more about emission spectrum, refer the link below:
https://brainly.com/question/27268130
#SPJ2
Nitrogen and water react to form nitrogen monoxide and hydrogen, like this: N2(g) + 2H2O(g) → 2NO(g) +2H2(g) Also, a chemist finds that at a certain temperature the equilibrium mixture of nitrogen, water, nitrogen monoxide, and hydrogen has the following composition: compound concentration at equilibrium H20 NO H2 0.25 M 1.3 M 0.33 M 1.2 M Calculate the value of the equilibrium constant Kc for this reaction. Round your answer to 2 significant digits
Answer:
Kc for this reaction is 0.43
Explanation:
This is the equilibrium:
N₂(g) + 2H₂O(g) → 2NO(g) +2H₂(g)
And we have all the concentration at equilibrium:
N₂: 0.25M
H₂ : 1.3M
NO: 0.33M
H₂: 1.2M
They are ok, because they are in MOLARITY. (mol/L)
Let's make the expression for Kc
Kc = ( [NO]² . [H₂]² ) / ([N₂] . [H₂O]²)
Kc = (0.33² . 1.2²) / (0.25 . 1.2²)
Kc = 0.4356
In two significant digits. 0.43
Final answer:
To calculate the equilibrium constant (Kc) for the reaction between nitrogen and water to form nitrogen monoxide and hydrogen, the concentration of nitrogen at equilibrium is required, which was not provided in the question.
Explanation:
The chemical equation for the reaction between nitrogen and water to form nitrogen monoxide and hydrogen is given by:
N2(g) + 2H2O(g) -> 2NO(g) + 2H2(g)
The equilibrium constant (Kc) for this reaction can be calculated using the concentrations of the reactants and products at equilibrium:
Kc = [NO]2 * [H2]2 / ([N2] * [H2O]2)
Substituting the given equilibrium concentrations into the equation:
Kc = (1.3 M)2 * (0.33 M)2 / ([N2] * (0.25 M)2)
However, we do not have the concentration of N2 at equilibrium provided in the question. The student needs to provide this concentration to calculate the value of Kc.
In the laboratory a student uses a "coffee cup" calorimeter to determine the specific heat of a metal.
She heats 19.5 grams of tungsten to 97.80°C and then drops it into a cup containing 78.3 grams of water at 22.58°C. She measures the final temperature to be 23.20°C.
Assuming that all of the heat is transferred to the water, she calculates the specific heat of tungsten to be J/g°C.
Answer : The specific heat of tungsten is, [tex]0.139J/g^oC[/tex]
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
[tex]q_1=-q_2[/tex]
[tex]m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)[/tex]
where,
[tex]c_1[/tex] = specific heat of tungsten = ?
[tex]c_2[/tex] = specific heat of water = [tex]4.18J/g^oC[/tex]
[tex]m_1[/tex] = mass of tungsten = 19.5 g
[tex]m_2[/tex] = mass of water = 78.5 g
[tex]T_f[/tex] = final temperature = [tex]23.20^oC[/tex]
[tex]T_1[/tex] = initial temperature of tungsten = [tex]97.80^oC[/tex]
[tex]T_2[/tex] = initial temperature of water = [tex]22.58^oC[/tex]
Now put all the given values in the above formula, we get
[tex]19.5g\times c_1\times (23.20-97.80)^oC=-78.5g\times 4.18J/g^oC\times (23.20-22.58)^oC[/tex]
[tex]c_1=0.139J/g^oC[/tex]
Therefore, the specific heat of tungsten is, [tex]0.139J/g^oC[/tex]
A second- order reaction of the type A + B -->P was carried out in a solution that was initially 0.075 mol dm^-3 in A and 0.050 mol dm^-3 in B. After 1.0 h the concentration of A had fallen to 0.020 mol dm^-3. a) Calculate the Rate constant. b) Solve for the half- life of each of the reactants.
Hint: Answers are a) 16.2 dm^3/mol*h
b) 5.1 × 10^3 s, 2.1 × 10^3 s
The rate constant (k) is 16.2 dm³/mol·h. The half-life of reactant A is 5.1 × 10³ s and the half-life of reactant B is 2.1 × 10³ s.
Explanation:To calculate the rate constant (k) of a second-order reaction, we can use the integrated rate law:
1/[A] - 1/[A]₀ = kt
Where [A] is the concentration of A at time t, [A]₀ is the initial concentration of A, k is the rate constant, and t is the time. Rearranging this equation, we get:
k = (1/[A] - 1/[A]₀) / t
Substituting the given values, k = (1/0.020 - 1/0.075) / 1.0 = 16.2 dm³/mol·h.
To find the half-life of each reactant, we can use the equation:
t½ = 1 / (k * [A]₀)
For reactant A, t½ = 1 / (16.2 * 0.075) = 5.1 × 10³ s.
For reactant B, t½ = 1 / (16.2 * 0.050) = 2.1 × 10³ s.
Learn more about Rate constant and half-life here:https://brainly.com/question/31490607
#SPJ12
The rate constant for this second-order reaction is 16.2 dm^3/mol*h, and the half-lives of reactants A and B are 5.1 × 10^3 s and 2.1 × 10^3 s respectively.
Explanation:The rate constant for a second-order reaction can be calculated using the formula: k = 1 / ((1 / [A]2 - 1 / [A]1) * t). Here, [A]1 is the initial concentration of A (0.075 mol dm^-3), [A]2 is the final concentration of A (0.020 mol dm^-3), and t is the time elapsed (1.0 h). Plugging these values into the formula gives a rate constant, k = 1 / ((1 / 0.020 - 1 / 0.075) * 1.0)= 16.2 dm^3/mol*h.
For a second-order reaction, the half-life can be determined by the formula: t1/2 = 1 / (k * [A]0). Therefore, the half lives for reactants A and B are as follows: t1/2A = 1 / (16.2 * 0.075)≈ 0.820 h or 5.1 × 10^3 s and t1/2B = 1 / (16.2 * 0.050) ≈ 1.235 h or 2.1 × 10^3 s. Hence, the rate constant and half-lives of the reactants have been calculated using the provided concentrations and the second-order reaction rate law.
Learn more about Second-Order Reaction Kinetics here:https://brainly.com/question/32870205
#SPJ11
What purpose do each of the following play in the isolation and purification of ethyl 3- hydroxybutanoate?
a. Filtration with filter aid
b. Extraction with 3 portions of diethyl ether
c. Anhydrous sodium sulfate
d. Evaporation in the hood
Explanation:
-Filter help — delete some big unreacted, undesirable species (norit is probably from what you are sorting through, its only carbon which cleans up things)
— extract with DCM because you are probably in an aqueous phase, and some butanoate is in it
- Anhydrous sodium absorbs excess of water (dries the material)
-evaporation in the hood to clear the DCM and crystallize the product.
The K b Kb for an amine is 4.004 × 10 − 5 . 4.004×10−5. What percentage of the amine is protonated if the pH of a solution of the amine is 9.370 9.370 ? Assume that all OH − OH− came from the reaction of B with H 2 O . H2O. percentage protonated: %
Answer:
The percentage of amine is protonated is 63,07%
Explanation:
The reaction of an amine RNH₃ (weak base) with water is:
RNH₃ + H₂O ⇄ RNH₄⁺ + OH⁻
The kb is defined as:
[tex]kb = \frac{[RNH_{4}^+][OH^-]}{[NH_{3}]}[/tex]
As kb = 4,004x10⁻⁵ and [OH⁻] is [tex]10^{-(14-9,370)}=2,344x10^{-5}[/tex]:
[tex]4,004x10^{-5} = \frac{[RNH_{4}^+][2,34x10^{-5}]}{[NH_{3}]}[/tex]
1,708 = [RNH₄⁺] / [RNH₃] (1)
As the total amine is a 100%:
[RNH₄⁺] + [RNH₃] = 100% (2)
Replacing (1) in (2):
1,708 [RNH₃]+ [RNH₃] = 100%
2,708 [RNH₃] = 100%
[RNH₃] = 36,93%
Thus,
[RNH₄⁺] = 63,07%
The percentage of amine protonated is 63,07%
I hope it helps!
The percentage of the amine protonated at a pH of 9.370, with Kb of 4.004 × 10⁻⁵, is approximately 63%.
Use the relationship pKa + pKb = 14 to find the pKa of the amine's conjugate acid:
pKa = 14 - pKb
pKb = -log(Kb) = -log(4.004 × 10⁻⁵) = 4.397
pKa = 14 - 4.397 = 9.603
The Henderson-Hasselbalch equation can now be used to find the ratio of protonated to unprotonated forms:
pH = pKa + log([A⁻]/[HA])
9.370 = 9.603 + log([A⁻]/[HA])
-0.233 = log([A⁻]/[HA])
[A⁻]/[HA] = 10⁻⁰·²³³ ≈ 0.588
The fraction of the amine that is protonated ([HA]) can be found by considering:
fraction protonated ([HA]) = [HA] / ([HA] + [A⁻])
Let [HA] = x and [A⁻] = 0.588x, so:
fraction protonated ([HA]) = x / (x + 0.588x) = 1 / (1 + 0.588) ≈ 0.63
Therefore, the percentage protonated is approximately:
63%
If you drop Mg into HCl, you will evolve hydrogen gas. If you perform this reaction over water at a temperature of 298.15 K at a pressure of 0.977 atm, and the vapor pressure of water at this temperature is 0.0313 atm, what is the pressure of hydrogen?
A.718.7 mm Hg
B.760.0 mm Hg
C.742.5 mm Hg
D.766.3 mm Hg
Answer:
The pressure of hydrogen is 718.7 mmHg. (option a)
Explanation:
Total pressure on the system is 0.977 atm.
Vapor pressure of water is 0.0313 atm, so
H₂ pressure = Total pressure - Vapor pressure
H₂ pressure = 0.977 atm - 0.0313 atm = 0.9457 atm
Let's convert atm to mmHg
1 atm ____ 760 mmHg
0.9457 atm ____ (0.9457 atm . 760 mmHg) / 1
= 718.7 mmHg
Final answer:
The pressure of hydrogen gas when Mg is dropped into HCl over water at 298.15 K and 0.977 atm, with a water vapor pressure of 0.0313 atm, is found to be closest to 718.7 mm Hg after using Dalton's Law of Partial Pressures and converting atm to mmHg.
Explanation:
To determine the pressure of hydrogen gas evolved when Mg is dropped into HCl over water, we need to use Dalton's Law of Partial Pressures which states that the total pressure exerted by a mixture of non-reacting gases is equal to the sum of the partial pressures of individual gases.
Using the given data: the total pressure is 0.977 atm, and the water vapor pressure at 298.15 K is 0.0313 atm. To find the hydrogen gas pressure, we subtract the water vapor pressure from the total pressure:
Pressure of hydrogen = Total pressure - water vapor pressure
Pressure of hydrogen = 0.977 atm - 0.0313 atm
Pressure of hydrogen = 0.9457 atm
Now convert the pressure from atm to mmHg, knowing that 1 atm = 760 mmHg:
Pressure of hydrogen = 0.9457 atm × 760 mmHg/atm
Pressure of hydrogen = 718.13 mm Hg
Therefore, the closest answer to the calculated pressure of hydrogen is 718.7 mm Hg, which corresponds to option A.
A strain of Escherichia coli has been genetically engineered to produce human protein. A batch culture is started by inoculating 12 g of cells into a 100-litre bubble column fermenter containing 10 g 1^- 1 glucose. The culture does not exhibit a lag phase. The maximum specific growth rate of the cells is 0.9 h^-1; the biomass yield from glucose is 0.575 g g^-1
1. Estimate the time required to reach stationary phase.
2. What will be the final cell density if the fermentation is stopped after only 70% of the substrate is consumed?
Answer:
1. 4.32 h
2. 4.12 g/L
Explanation:
1. For a batch culture, the time (tb) can be calculated by:
tb = ln (X/X0)/μmax
Where X0 is the initial mass concentration of the cells (12 g/100L = 0.12 g/L), X is the mass concentration of the cells at tb, and μmax is the maximum specific growth rate of the cells.
The biomass yield (Y) is:
Y = (X - X0)/ (S0 - S)
Where S is the mass concentration of the substrate at tb and S0 the initial mass concentration of the substrate (glucose in this case).
Reorganizing:
X = Y*(S0 -S) + X0
Let's assume that at the stationary state all substrate was consumed, so S = 0.
tb = ln[(YS0 + X0)/X0)]/μmax
tb = ln[(0.575*10 + 0.12)/0.12]/0.9
tb = 4.32 h
2. If 70% of the substrate is consumed, S = 10 - 0.7*10 = 3 g/L
tb = ln[(0.575*(10-3) + 0.12)/0.12]/0.9
tb = 3.93 h
The initial concentration is X0 = 0.12 g/L, the X:
tb = ln (X/X0)/μmax
3.93 = ln(X/0.12)/0.9
ln(X/0.12) = 3.537
X/0.12 = [tex]e^{3.537}[/tex]
X/0.12 = 34.36
X = 4.12 g/L
Answer:
a) to = 4.3 h
b) xf = 4.1 g/L
Explanation:
We have the following data:
So = 10 g*L^-1 = initial concentration
Ys = biomass yield = 0.575 g*g^-1
umax = maximum specific growth rate = 0.9 h^-1
The initial cell concentration is equal to:
xo = 12 g/100 L = 0.12 g/L
a) The batch time it takes to reach the stationary phase equals:
to = (1/umax)*ln(1 + (Ys*(so-sf)/xo))) = (1/0.9)*ln(1+(0.575*(10-0))/0.12)))) = 4.3 h
b) Since the fermentation stops after consuming only 70% of the glucose, we have the following:
sf = (1-07)*so = 0.3*10 = 3 g/L
tb = (1/0.9)*ln(1+(0.575*(10-3))/(0.12)))) = 3.94 h
Finally, the final cell concentration can be found by the following equation:
xf = xo*e^(umax * tb) = 0.12 * e^(0.9 * 3.94) = 4.1 g/L
Be sure to answer all parts. The net change in the multistep biochemical process of photosynthesis is that CO2 and H2O form glucose (C6H12O6) and O2. Chlorophyll absorbs light in the 600 to 700 nm region. What is the minimum number of photons with 680. nm needed to prepare 1.00 mol of glucose? Assume CO2 to be a gas and glucose to be a solid.
Answer:
9.86 × 10²⁴ photons
Explanation:
Let's consider the photosynthesis global reaction.
6 CO₂(g) + 6 H₂O(l) → C₆H₁₂O₆(s) + 6 O₂(g)
We can calculate the standard Gibbs free energy of the reaction (ΔG°) using the following expression.
ΔG° = ∑np . ΔG°f(p) - ∑nr . ΔG°f(r)
where,
ni are the moles of reactants and products
ΔG°f(p) are the standard free Gibbs energies of formation of reactants and products
For the balanced equation for 1.00 mol of glucose, ΔG° is:
ΔG° = [1 mol × ΔG°f(C₆H₁₂O₆(s)) + 6 mol × ΔG°f(O₂(g))] - [6 mol × ΔG°f(CO₂(g)) + 6 mol × ΔG°f(H₂O(l))]
ΔG° = [1 mol × (-910.6 kJ/mol) + 6 mol × 0 kJ/mol] - [6 mol × (-394.4 kJ/mol) + 6 mol × (-237.1 kJ/mol)]
ΔG° = 2878 kJ
The energy of each photon (E) can be calculated using the Planck-Einstein's equation.
E = h . c. λ⁻¹
where,
h is the Planck's constant
c is the speed of light
λ is the wavelength
E = (6.626 × 10⁻³⁴ J.s) × (3.00 × 10⁸ m/s) × (680 × 10⁻⁹ m)⁻¹ = 2.92 × 10⁻¹⁹ J
The minimum number of photons required is:
[tex]2878\times 10^{3} J.\frac{1photon}{2.92\times 10^{-19}J} =9.86 \times 10^{24}photon[/tex]
Final answer:
The net change in photosynthesis involves forming glucose and O2 from CO2 and H2O with the aid of solar energy. The minimum number of photons needed at 680 nm to form 1.00 mol of glucose can be calculated using the energy requirements for the synthesis of glucose in photosynthesis.
Explanation:
The question pertains to the light-dependent reactions of photosynthesis, where solar energy is absorbed by chlorophyll to produce glucose from CO2 and H2O. Calculating the minimum number of photons with a wavelength of 680 nm needed to prepare 1.00 mol of glucose requires understanding the energy associated with photons and the process of photosynthesis. Since solar energy is converted into chemical energy in the form of ATP and NADPH during photosynthesis, and a total of 54 ATP equivalents are required to synthesize one molecule of glucose, the number of photons must provide at least this much energy. Considering that each photon's energy is inversely proportional to its wavelength, we can use the relationship E = hc/λ (where E is energy, h is Planck's constant, c is the speed of light, and λ is wavelength) to calculate the energy of a photon of 680 nm, and subsequently, determine the total number of photons required to provide the 54 ATP equivalents needed for glucose synthesis.
What is the purpose of adding phenolphthalein to your Erlenmeyer flask prior to starting a titration?
a. The phenolphthalein acts as a color changing indicator to signal the endpoint of the reaction.
b. The phenolphthalein will change color once we have added the correct amount of base to our acid.
c. The phenolphthalein acts as an acid in the neutralization reaction.
d. The phenolphthalein acts as a base in the neutralization reaction.
Answer:
a. The phenolphthalein acts as a color changing indicator to signal the endpoint of the reaction.
Explanation:
Phenolphthalein is an organic substance with chemical formula [tex]C_{20}H_{14}O_{4}[/tex].
It is a substance commonly used in acid-base titrations to indicate the end point in the titration because phenolphthalein is colorless in acidic solutions but turns a purplish-pink color in basic solutions.
In this way it helps visually to notice when the final point of the titration has been reached.
Phenolphthalein is added to an Erlenmeyer flask in a titration to act as a color-changing indicator that signals the endpoint of the reaction by turning from colorless to pink as the solution transitions from acidic to basic conditions, close to the equivalence point.
Explanation:The purpose of adding phenolphthalein to an Erlenmeyer flask prior to starting a titration is essentially to serve as a color-changing indicator that signals the endpoint of the reaction. When used in an acid-base titration, phenolphthalein shifts in color from colorless in acidic conditions to pink in basic conditions. This color transition happens around a pH of 8.2 to 10, indicating that the solution has reached an alkaline environment which, for many titrations, corresponds closely to the equivalence point.
In titrations, the correct amount of titrant (a solution of known concentration) is added slowly to a solution until the reaction reaches its endpoint, which is often near the equivalence point. An indicator like phenolphthalein undergoes a sharp color change at a specific pH range, making it easier to determine when the reaction has reached this point. The precise moment of color change is critical in determining the exact volume of titrant added, essential for calculating the concentration of the unknown solution.
Which statement about boiling point is FALSE?
The boiling point is higher for compounds with a high viscosity.
The boiling point of a compound is an absolute constant.
The boiling point is higher for compounds with strong intermolecular forces.
The boiling point of a compound is higher for nonvolatile compounds.
All of the above statements are true.
Answer: The boiling point of water is an absolute constant
Explanation:
The boiling point of a compound is NOT an absolute constant. This is because at certain conditions such as a change in altitude, the boiling point of a compound changes.
As temperature increases, evaporation increases and vapour pressure increases. Compounds boils when vapour pressure equal to the atmospheric pressure.
At higher altitudes, atmospheric pressure is decreses.
When atmospheric pressure is decresed, the vapour pressure of the compound is lowered to reach boiling point. Therefore, the temperature needed for vapour pressure to equal atmospheric pressure is lower. The boiling point is lower at higher altitude.
Hence boiling point depends on atmospheric pressure
The boiling point of a compound is not an absolute constant.
Explanation:The statement "The boiling point of a compound is an absolute constant" is FALSE.
The boiling point of a compound is affected by several factors, including intermolecular forces and molecular structure. Compounds with stronger intermolecular forces, such as hydrogen bonds, will generally have higher boiling points. Viscosity, which is the resistance of a liquid to flow, is not directly related to boiling point. Nonvolatile compounds, which do not easily evaporate, may have lower boiling points depending on their molecular structure.
Therefore, the correct statement is that the boiling point is not an absolute constant.
Learn more about boiling point here:https://brainly.com/question/34261956
#SPJ3
From each of the following pairs of substances, use data in Appendix E in the textbook to choose the one that is the stronger oxidizing agent.Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.1. Given HO2- (aq) or O3 (g), the stronger oxidizing agent is _____.2. Given Cl2 (g) or I2 (s), the stronger oxidizing agent is _____.3. Given Zn^2+ (aq) or Co^2+ (aq), the stronger oxidizing agent is _____.4. Given Br2 (l) or BrO3- (aq), the stronger oxidizing agent is _____.WORD BOX:Zn^2+ (aq)O3 (g)I2 (s)HO2- (aq)Cl2 (g)Br2 (l)Co^2+ (aq)BrO3- (aq)
To determine the stronger oxidizing agent in each pair of substances, compare the oxidizing strengths using data from Appendix E. The stronger oxidizing agents are O3(g), Cl2(g), Co2+(aq), and BrO3-(aq).
Explanation:To determine the stronger oxidizing agent in each pair, we need to compare the oxidizing strengths of the substances. From Appendix E in the textbook, we can find the relevant data. Here are the answers:
Given HO2- (aq) or O3 (g), the stronger oxidizing agent is O3 (g).Given Cl2 (g) or I2 (s), the stronger oxidizing agent is Cl2 (g).Given Zn2+ (aq) or Co2+ (aq), the stronger oxidizing agent is Co2+ (aq).Given Br2 (l) or BrO3- (aq), the stronger oxidizing agent is BrO3- (aq).Learn more about Oxidizing agents here:https://brainly.com/question/10547418
#SPJ12
To determine the stronger oxidizing agent, compare the standard reduction potentials of the species in each pair. The substance with the higher standard reduction potential is the stronger oxidizing agent.
Explanation:To determine the stronger oxidizing agent in each pair, we need to compare their standard reduction potentials. The substance with the higher standard reduction potential is the stronger oxidizing agent. From Appendix E, we can find the standard reduction potentials of the species in each pair and compare them to determine the stronger oxidizing agent.
Given HO2- (aq) or O3 (g), the stronger oxidizing agent is O3 (g).Given Cl2 (g) or I2 (s), the stronger oxidizing agent is Cl2 (g).Given Zn2+ (aq) or Co2+ (aq), the stronger oxidizing agent is Co2+ (aq).Given Br2 (l) or BrO3- (aq), the stronger oxidizing agent is BrO3- (aq).Learn more about Determining stronger oxidizing agents here:https://brainly.com/question/31950814
#SPJ11
Calculate the number of milliliters of 0.587 M NaOH required to precipitate all of the Ni2+ ions in 163 mL of 0.445 M NiBr2 solution as Ni(OH)2. The equation for the reaction is: NiBr2(aq) + 2NaOH(aq) Ni(OH)2(s) + 2NaBr(aq) mL NaOH Submit AnswerRetry Entire Group
Answer:
We need 247 mL of NaOH
Explanation:
Step 1: Data given
Molarity of NaOH = 0.587 M
Volume of 0.445 M NiBr2 solution = 163 mL = 0.163 L
Step 2: The balanced equation
NiBr2(aq) + 2NaOH(aq) Ni(OH)2(s) + 2NaBr(aq)
Step 3: Calculate moles of NiBr2
Moles NiBR2 = Molarity NiBR2 * volume
Moles NiBR2 = 0.445 M * 0.163 L
Moles NiBR2 = 0.0725 moles
Step 3: Calculate moles of NaOH
For 1 mol NiBr2 consumed, we need 2 moles NaOH
For 0.0725 moles NiBR2, we need 2* 0.0725 = 0.145 moles NaOH
Step 4: Calculate volume of NaOH
Volume = moles NaOH / Molarity NaOH
Volume = 0.145 moles / 0.587 M
volume = 0.247L = 247 mL
We need 247 mL of NaOH
Which of the statements about enzymes are true?
a. Nonbiological catalysts and enzymes tend to have a similar degree of reaction specificity.
b. Catalysis occurs at the active site, which usually consists of a crevice on the surface of the enzyme.
c. Generally, an enzyme is specific for a particular substrate. For example, thrombin catalyzes the hydrolysis of the peptide bond between Arg and Gly.
Answer: b. Catalysis occurs at the active site, which usually consists of a crevice on the surface of the enzyme.
c. Generally, an enzyme is specific for a particular substrate. For example, thrombin catalyzes the hydrolysis of the peptide bond between Arg and Gly.
Explanation:
The role of the enzyme is to produce a specific product, whereas the non-biological catalyst produces more than one product. Thus they have a different degree of reaction specificity.
The active site of the enzyme is the catalytic site of the enzyme. It is the region where the substrate molecule bind and undergoes a chemical reaction. The enzyme exhibit a special crevice or opening at the active site which facilitates the binding with the substrate.
Enzymes usually bind to a specific substrate as they have an active site that allows a particular substrate to bind to the active site of the enzyme. This is because of the shape of the active site of the enzyme which has a binding affinity with a particular substrate any other substrate cannot bind to the active site.
A 1.40 L sample of O2 at 645 Torr and 25 °C, and a 0.751 L sample of N2 at 1.13 atm and 25 °C, are both transferred to the same 2.00 L container at 25 °C. What are the partial pressures of the two gases and the total pressure inside the 2.00 L container? Show your work.
Answer:
P(O₂) = 0.595 atmP(N₂) = 0.424 atmTotal Pressure = 1.019 atmExplanation:
To solve this problem we use PV=nRT for both gases in their containers, in order to calculate the moles of each one:
O₂:645 Torr ⇒ 645 /760 = 0.85 atm
25°C ⇒ 25 + 273.16 = 298.16 K
0.85 atm * 1.40 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ *298.16 K
n = 0.0487 mol O₂
N₂:1.13 atm * 0.751 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ *298.16 K
n = 0.0347 mol N₂
Now we can calculate the partial pressure for each gas in the new container, because the number of moles did not change:
O₂:P(O₂) * 2.00 L = 0.0487 mol O₂ * 0.082 atm·L·mol⁻¹·K⁻¹ *298.16 K
P(O₂) = 0.595 atm
N₂:P(N₂) * 2.00 L = 0.0347 mol N₂ * 0.082 atm·L·mol⁻¹·K⁻¹ *298.16 K
P(N₂) = 0.424 atm
Finally we add the partial pressures of all gases to calculate the total pressure:
Pt = 0.595 atm+ 0.424 atm = 1.019 atmFinal answer:
To find the partial pressures and total pressure in the container, convert pressures to atm, apply the ideal gas law for each gas, and sum the resulting partial pressures. The partial pressures are 0.5959 atm for O₂ and 0.4249 atm for N₂, with a total pressure of 1.0208 atm.
Explanation:
The question asks to calculate the partial pressures of O₂ and N₂ as well as the total pressure in a 2.00 L container at 25 °C, after transferring 1.40 L of O₂ at 645 Torr and 0.751 L of N₂ at 1.13 atm into it. To solve this, the pressure values need to be converted to a common unit (atmospheres), and the ideal gas law used for calculations.
First, convert the O₂ pressure from Torr to atm: 645 Torr / 760 = 0.8487 atm. Then use the ideal gas law (P₁V₁ = P₂V₂) to find the new pressures in the 2.00 L container. For O₂, (0.8487 atm)(1.40 L) / 2.00 L = 0.5959 atm. The pressure of N₂ is already in atm, so, (1.13 atm)(0.751 L) / 2.00 L = 0.4249 atm.
The total pressure is the sum of the partial pressures: 0.5959 atm (O₂) + 0.4249 atm (N₂) = 1.0208 atm. Therefore, the partial pressures are 0.5959 atm for O₂ and 0.4249 atm for N₂, with a total pressure of 1.0208 atm in the container.
Which of the following best defines molar heat capacity. a. The quantity of heat required to lower the temperature of 1 liter of a substance by 1°C b.The quantity of heat required to raise the temperature of 1 gram of a substance by 1°F c. The quantity of heat required to raise the temperature of 1 gram of a substance by 1°C d, The quantity of heat required to raise the temperature of 1 mole of a substance by 1K
Answer:
d. The quantity of heat required to raise the temperature of 1 mole of a substance by 1K
Explanation:
Heat capacity is a physical property of matter that is defined as the quantity of heat supplied for a material to change in one unit its temperature. This heat depends of the amount of material.
For that reason, molar heat capacity is defined as:
d. The quantity of heat required to raise the temperature of 1 mole of a substance by 1K
Alluding molar to moles of a material or substance.
I hope it helps!
Consider a beaker containing a saturated solution of PbI2 in equilibrium with undissolved PbI2(s).
(a) If solid KI is added to this solution, will the amount of solid PbI2 at the bottom of the beaker increase, decrease, or remain the same?
(b) Will the concentration of Pb^2+ ions in solution increase or decrease?
(c) Will the concentration of I- ions in solution increase or decrease?
Answer:
(a) Increase the solid PbI₂ (s)
(b) Decrease
(c) Increase
Explanation:
In this question we are considering the effect of adding a common ion to an equilibrium.
The problem states that the saturated solution of PbI₂ is at equilibrium with undissolved PbI₂ (s) :
PbI₂ (s) ⇄ Pb²⁺+ 2 I⁻
If we increase the concentration of I⁻ by adding the highly soluble KI , the equilibrium will react according to LeChatelier´s principle by decreasing the concentration of Pb²⁺ precipitating some Pb²⁺ until it reaches equilibrium again. With this in mind, lets answer the question:
(a) Increase the solid PbI₂ (s)
(b) Decrease
(c) Increase
The addition of KI in the solution increases the settling of lead iodide at the bottom, decreases the lead ions and increases the iodide ions in the solution.
What is a saturated solution?The saturated solution has been given as the one in which the salt has been divided into maximum concentration.
The equilibrium reaction of lead iodide has been:
[tex]\rm PbI_2\;\rightleftharpoons Pb^2^+\;+2\;I^-[/tex]
The addition of KI increases the product concentration, and the lead iodide has been found to be settles in increased concentration in the bottom.
The addition of KI decreases the rate of formation of product, thus the ion of lead formation will be decreased in the reaction.
The concentration of iodide ions in the solution increases with the addition of KI with common ion effect.
Learn more about common ion effect, here:
https://brainly.com/question/4090548
The carbon atoms of acetic acid (CH3COOH) exhibit what type of hybridization?
A.) sp
B.) sp^2
C.) sp^3
D.) sp^2 and sp^3
Answer:
The correct answer is D sp2 and sp3
Explanation:
Acetic acid is a weak acid containg 2 carbon atoms.the first carbon is joined to 3 hydrogen atoms by 3 covalent bonds and to the second carbo atom by one covalent bond.Therefore the first carbon of CH3COOH is sp3 hybridized.
Whereas the second carbon is joined to the first carbon by a covalent bond,the second carbon form a double bond with oxygen and thesecond carbon forms a covalent bond with the oxygen atom of -OH group of COOH moiety.Therefore the second carbon is sp2 hybridized.
The type of hybridization that the carbon atoms of acetic acid (CH3COOH) exhibit include sp² and sp³.
Acetic acid is also referred to as ethanoic acid. It is a colorless liquid and an important chemical reagent used in the production of fabrics, synthetic fibers, and photographic film.
It has 2 carbon atoms. It should be noted that the first carbon is joined to 3 hydrogen atoms by 3 covalent bonds and to the second carbon atom by one covalent bond.
The second carbon is joined to the first carbon by a covalent bond and the second carbon forms a double bond with oxygen. Therefore, the types of hybridization exhibited for the carbon atoms are sp² and sp³.
Read related link on:
https://brainly.com/question/13980678
What volume would be occupied by 4.8 g of oxygen gas at 0.50 atm and 133°C? Hint: Determine moles of oxygen gas first.
The volume that would be occupied by oxygen gas is equal to 10 Liters
Given the following data:
Mass = 4.8 g
Pressure = 0.50 atm
Temperature = 133°C to K = [tex]273+133 =406\;K[/tex]
Scientific data:
Molar mass of oxygen gas = 32 g/mol.
Ideal gas constant, R = 0.0821L⋅atm/mol⋅K
To determine the volume that would be occupied by oxygen gas:
First of all, we would determine the number of moles of oxygen gas present.
[tex]Number\;of\;moles = \frac{mass}{molar\;mass}\\\\Number\;of\;moles = \frac{4.8}{32}[/tex]
Number of moles = 0.15 moles
Now, we can find the volume of oxygen gas by the ideal gas law equation;
[tex]V = \frac{nRT}{P} \\\\V=\frac{0.15 \times 0.0821 \times 406}{0.5} \\\\V=\frac{4.99989}{0.5}[/tex]
Volume = 10 Liters
Read more: https://brainly.com/question/13442572
The dissociation of sulfurous acid (H2SO3) in aqueous solution occurs as follows:
H2SO3 ---> H+ + HSO3-
HSO3- ---> H+ + SO32-
If .50 moles of sulfurous acid are dissolved to form a 1 L solution, which of the following concentrations will be LEAST at equilibrium?
A.) [H2SO3]
B.) [H+]
C.) [H3O+]
D.) [SO32-]
Answer:
The [SO₃²⁻]
Explanation:
From the first dissociation of sulfurous acid we have:
H₂SO₃(aq) ⇄ H⁺(aq) + HSO₃⁻(aq)
At equilibrium: 0.50M - x x x
The equilibrium constant (Ka₁) is:
[tex] K_{a1} = \frac{[H^{+}] [HSO_{3}^{-}]}{[H_{2}SO_{3}]} = \frac{x\cdot x}{0.5 - x} = \frac {x^{2}}{0.5 -x} [/tex]
With Ka₁= 1.5x10⁻² and solving the quadratic equation, we get the following HSO₃⁻ and H⁺ concentrations:
[tex] [HSO_{3}^{-}] = [H^{+}] = 7.94 \cdot 10^{-2}M [/tex]
Similarly, from the second dissociation of sulfurous acid we have:
HSO₃⁻(aq) ⇄ H⁺(aq) + SO₃²⁻(aq)
At equilibrium: 7.94x10⁻²M - x x x
The equilibrium constant (Ka₂) is:
[tex] K_{a2} = \frac{[H^{+}] [SO_{3}^{2-}]}{[HSO_{3}^{-}]} = \frac{x^{2}}{7.94 \cdot 10^{-2} - x} [/tex]
Using Ka₂= 6.3x10⁻⁸ and solving the quadratic equation, we get the following SO₃⁻ and H⁺ concentrations:
[tex] [SO_{3}^{2-}] = [H^{+}] = 7.07 \cdot 10^{-5}M [/tex]
Therefore, the final concentrations are:
[H₂SO₃] = 0.5M - 7.94x10⁻²M = 0.42M
[HSO₃⁻] = 7.94x10⁻²M - 7.07x10⁻⁵M = 7.93x10⁻²M
[SO₃²⁻] = 7.07x10⁻⁵M
[H⁺] = 7.94x10⁻²M + 7.07x10⁻⁵M = 7.95x10⁻²M
So, the lowest concentration at equilibrium is [SO₃²⁻] = 7.07x10⁻⁵M.
I hope it helps you!
When .50 moles of sulfurous acid are dissolved in a 1 L solution, the concentration that will be least at equilibrium is [H2SO3].
In the given equilibrium reactions, when .50 moles of sulfurous acid are dissolved in a 1 L solution, the concentration that will be LEAST at equilibrium is [H2SO3], which represents the original acid concentration.
Cars run on gasoline, where octane (C8H18) is the principle component. This combustion reaction is responsible for generating enough energy to move a vehicle, or do other work.
How much CO2 and H2O (in grams) are produced in the combustion of 1.24 gallons of Octane? (density = 0.703 g/mL)
Helpful conversion, there are 4 quarts in a gallon. Beyond that, check out your equation sheet for other useful conversion factors!
To determine the amount of CO2 and H2O produced in the combustion of 1.24 gallons of octane (C8H18), convert the volume to grams using the given density. Then, balance the combustion equation and calculate the mole ratio. Finally, use the mole ratio to calculate the grams of CO2 and H2O produced.
Explanation:To determine the amount of CO2 and H2O produced in the combustion of 1.24 gallons of octane (C8H18), we need to use stoichiometry and conversion factors. First, convert the volume of octane from gallons to milliliters, then to grams using the given density. Next, balance the combustion equation and determine the mole ratio between octane, CO2, and H2O. Finally, use the mole ratio to calculate the grams of CO2 and H2O produced.
Step 1: Convert gallons to milliliters:
1.24 gallons x 4 quarts/gallon x 946.35 mL/quart = 4687.01 mLStep 2: Convert milliliters to grams:
4687.01 mL x 0.703 g/mL = 3289.44 gStep 3: Balance the combustion equation:
C8H18 + 12.5 O2 -> 8 CO2 + 9 H2OStep 4: Calculate mole ratio:
1 mole of octane produces 8 moles of CO2 and 9 moles of H2OStep 5: Calculate grams of CO2 and H2O produced:
3289.44 g of octane x (8 mol CO2/1 mol octane) x (44.01 g/mol CO2) = 11630.13 g of CO23289.44 g of octane x (9 mol H2O/1 mol octane) x (18.02 g/mol H2O) = 53127.65 g of H2OLearn more about combustion of octane here:
https://brainly.com/question/1418637
#SPJ12
To find the amount of CO2 and H2O produced in the combustion of 1.24 gallons of octane, convert the volume to grams using the density of octane. Then, use the balanced equation to calculate the moles of octane, CO2, and H2O. Finally, convert the moles to grams using their respective molar masses.
Explanation:To calculate the amount of CO2 and H2O produced in the combustion of 1.24 gallons of octane, we need to convert the volume of octane to grams using its density. First, convert 1.24 gallons to quarts by multiplying it by 4 (since there are 4 quarts in a gallon). This gives us 4.96 quarts. Next, convert quarts to milliliters by multiplying by 946.35 (since there are approximately 946.35 milliliters in a quart). This gives us 4685.24 mL. Finally, multiply the volume in milliliters by the density of octane (0.703 g/mL) to get the mass of octane in grams. This comes out to be 3289.02 grams.
Now, let's consider the balanced equation for the combustion of octane:
C8H18 + 12.5O2 -> 8CO2 + 9H2O
From the balanced equation, we can see that for every 1 mole of octane, 8 moles of CO2 and 9 moles of H2O are produced. To find the number of moles of octane in 3289.02 grams, divide the mass by the molar mass of octane:
3289.02g / 114.22g/mol = 28.8 mol of octane
Now, multiply the number of moles of octane by the stoichiometric coefficients from the balanced equation to find the number of moles of CO2 and H2O:
CO2: 28.8 mol octane x 8 mol CO2 / 1 mol octane = 230.4 mol CO2
H2O: 28.8 mol octane x 9 mol H2O / 1 mol octane = 259.2 mol H2O
Finally, convert the number of moles of CO2 and H2O to grams by multiplying by their respective molar masses:
CO2: 230.4 mol CO2 x 44.01 g/mol = 10,134.74 g CO2
H2O: 259.2 mol H2O x 18.02 g/mol = 4,674.24 g H2O
Therefore, in the combustion of 1.24 gallons of octane, approximately 10,134.74 grams of CO2 and 4,674.24 grams of H2O are produced.
Learn more about Combustion of Octane here:https://brainly.com/question/1418637
#SPJ11
A 1.10 kg piece of granite with a specific heat of 0.803 J g-1 °C-1 and a temperature of 87.3 °C is placed into 2.00 L of water at 20.3 °C. When the granite and water come to the same temperature, what will the temperature be?
The final temperature of the granite and the water will be 26.6 °C.
Heat energy
In a mixture between two substances of different temperatures, there is heat transfer, in which the one with a lower temperature receives this heat and the one with a higher temperature loses the heat.
In a system, the value of heat lost and received is equal.
This heat is represented by the following expression:
[tex]Q = m \times c \times T[/tex]
The value of heat is given in calories, the value of temperature is given in celsius and the value of mass is given in grams
Thus, to find the value of the final temperature of the mixture, it is enough to equate the heat of the two substances.
[tex]1100 \times (\frac{0.803}{4,18}) \times (t_{f} - 83.7) = 2000 \times 1 \times (t_{f} - 20.3)[/tex]
[tex]220 (t_{f} - 83.7) = 2000 (t_{f} - 20.3)[/tex]
As the value of the granite final temperature is lower than the initial temperature, the result of the temperature variation would be negative, so the signs of the expression can be changed.
[tex]18414 - 220 t_{f} = 2000 t_{f} - 40600[/tex]
[tex]2220 t_{f} = 59,014[/tex]
[tex]t_{f} = 26.6[/tex]
So, the final temperature of the granite and the water will be 26.6 °C.
Learn more about heat energy in: brainly.com/question/1495272
Using conservation of energy, the final equilibrium temperature of the granite and water system can be calculated by setting the heat lost by granite equal to the heat gained by water and solving for the final temperature.
Explanation:The question is asking for the final equilibrium temperature of a two-part system initially at different temperatures when they are put in contact. This is a problem that can be solved using the concept of heat transfer and the principle of conservation of energy. The heat lost by the hot granite will equal the heat gained by the cooler water until thermal equilibrium is reached.
Using the specific heats of granite and water, and their masses and initial temperatures, we set up the equation based on the principle that heat lost = heat gained:
m1c1(Tfinal - T1(initial)) = m2c2(T2(initial) - Tfinal)
Where m1 and m2 are the masses of granite and water, c1 and c2 are their specific heats, Tfinal is the final equilibrium temperature and T1(initial) and T2(initial) are the initial temperatures of granite and water, respectively. You'll need to convert the mass of the granite to grams, as the specific heat is given in grams, and use the specific heat of water (4.184 J/g°C).
Then you can solve for Tfinal to find the temperature at which the granite and water reach equilibrium.
Galvanized nails are iron nails that have been plated with zinc to prevent rusting. The relevant reaction is
Zn2+(aq)+2e−→Zn(s)
For a large batch of nails, a manufacturer needs to plate a total zinc mass of 3.30 kg on the surface to get adequate coverage.
Part A
How many moles of zinc are in 3.30 kg of zinc?
Express your answer to three significant figures and include the appropriate units.
50.5 mol
SubmitHintsMy AnswersGive UpReview Part
Correct
Significant Figures Feedback: Your answer 50.47mol was either rounded differently or used a different number of significant figures than required for this part.
Answer:
50. 5mol
Explanation:
The mass of Zinc required = 3.30 kg = 3300 grams
The relation between moles and mass is:
[tex]moles=\frac{mass}{atomicmass}[/tex]
Atomic mass of Zinc = 65.38g/mol
[tex]molesofZinc=\frac{3300}{65.38}[/tex]
[tex]molesofzinc=50.47mol[/tex]
The answer to three significant figures will be 50.5 mol
To find the number of moles of zinc in 3.30 kg of zinc, divide the mass in grams by the molar mass of zinc. The number of moles of zinc is 50.5 mol.
Explanation:To find the number of moles of zinc in 3.30 kg of zinc, we can use the molar mass of zinc to convert the mass to moles. The molar mass of zinc (Zn) is 65.38 g/mol. First, we convert the mass from kg to g by multiplying by 1000:
3.30 kg × 1000 g/kg = 3300 g
Then, we divide the mass in grams by the molar mass to get the number of moles:
3300 g / 65.38 g/mol = 50.5 mol
Learn more about moles of zinc here:https://brainly.com/question/1070046
#SPJ3
The reaction of 50 mL of Cl2 gas with 50 mL of C2H4 gas via the equation: Cl2 (g) + C2H4 (g) → C2H4Cl2 (g) will produce a total of ________ mL of products if pressure and temperature are kept constant.
The reaction of 50 mL of Cl2 gas with 50 mL of C2H4 gas will produce 50 mL of C2H4Cl2 gas.
Explanation:In this reaction, the balanced equation tells us that 1 mole of Cl2 reacts with 1 mole of C2H4 to produce 1 mole of C2H4Cl2. Since the volumes of the gases are given, we can assume that the gases are at the same pressure and temperature. This means that the ratio of the volumes of the gases is the same as the ratio of the moles of the gases.
Therefore, if we have 50 mL of Cl2 gas and 50 mL of C2H4 gas, we would have 1 mole of Cl2 and 1 mole of C2H4. The reaction would produce 1 mole of C2H4Cl2, which is equivalent to 50 mL of C2H4Cl2 gas.
Hence, the total volume of products produced in this reaction would be 50 mL.
Learn more about Gas reaction here:https://brainly.com/question/31711830
#SPJ6
The reaction of 50 mL of Cl₂ gas with 50 mL of C₂H₄ gas under constant pressure and temperature produces 50 mL of C₂H₄Cl₂ gas as the product, following Avogadro's law.
Explanation:The question revolves around a chemical reaction where Cl₂ gas reacts with C₂H₄ gas to produce C₂H₄Cl₂ gas. According to Avogadro's law, at constant temperature and pressure, equal volumes of gases contain the same number of molecules. Hence, the volumes of gaseous reactants and products should be in the same ratio as their coefficients in the balanced chemical equation.
In this case, the chemical equation is:
Cl₂ (g) + C₂H₄ (g) → C₂H₄Cl₂ (g)
Each reactant has a coefficient of 1, indicating that they react on a one-to-one volume basis. This means that 50 mL of Cl₂ reacts with 50 mL of C₂H₄ to produce 50 mL of C₂H₄Cl₂. Since temperature and pressure are held constant, by Avogadro's principle, the volume of the products is the same as the volume of the reactants.
Therefore, the reaction of 50 mL of Cl₂ gas with 50 mL of C₂H₄ gas will produce a total of 50 mL of C₂H₄Cl₂ gas as the product.
Learn more about Chemical Reactions here:https://brainly.com/question/34137415
#SPJ3
A 52.4 g sample of brass is put into a calorimeter (see sketch at right) that contains 150.0 g of water. The brass sample starts off at 95.1 °C and the temperature of the water starts off at 15.0 °C. When the temperature of the water stops changing it's 17.6°C. The pressure remains constant at 1 atm. container water Calculate the specific heat capacity of brass according to this experiment.
Answer:
The specific heat capacity of brass is 0.402 J/g°C
Explanation:
Step 1: Data given
Mass of the sample of brass = 52.4 grams
Mass of water = 150.0 grams
Initial temperature of brass sample = 95.1 °C
Initial temperature of water = 15.0 °C
Final temperature = 17.6°C
Pressure = 1atm
Specific heat capacity = 4.184 J/g°C
Step 2: Calculate specific heat capacity of brass sample
Heat lost by the brass sample = heat won by water
Q = m*c*ΔT
Qbrass = -Qwater
m(brass)*c(brass)*ΔT(brass) = -m(water) *c(water) * ΔT(water)
⇒mass of brass sample = 52.4 grams
⇒ c(brass) = TO BE DETERMINED
⇒ ΔT = T2 - T1 = 17.6 °C - 95.1 °C = -77.5 °C
⇒ mass of water = 150.0 grams
⇒ c(water ) = 4.184 J/g°C
⇒ ΔT(water) = 17.6 °C - 15 °C = 2.6°C
52.4g * c(brass) * (-77.5°C) = -150.0g * 4.184 J/g°C * 2.6 °C
-4061 * c(brass) = -1631,76
c(brass) = 0.402 J/g°C
The specific heat capacity of brass is 0.402 J/g°C
12345678901234567890
A sealed isothermal container initially contained 2 moles of CO gas and 3 moles of H2 gas. The following reversible reaction occured: CO(g) + 2H2(g) ---> CH3OH(g). At equilibrium, there was 1 mole of CH3OH in the container. What was the total number of moles of gas present in the container at equilibrium.
A.) 1
B.) 2
C.) 3
D.) 4
Answer:
(c) Total Number of moles = 3
Explanation:
To solve this question we have to follow the stoichiometry of the reaction and the fact that at equilibrium we have 1 mol of CH₃OH using the mnemonic helper RICE ( Reaction, Initial, Change, Equilibrium) as follows:
R CO(g) + 2 H₂ (g) ⇄ CH₃OH (g)
I (mol) 2 3 0
C (mol) -x x -2x + x
E (mol) 2-x 3-2x x
But we are told that at equilibrium x = mol CH₃OH = 1 , then at equilibrium we will have
E (mol) 2-(1) 3-2(1) 1
E (mol) 1 1 1
Therefore, the total number of moles of gas present in the container at equilibrium was 3
The value of Ka for nitrous acid (HNO2) at 25 ∘C is 4.5×10−4 .a. Write the chemical equation for the equilibrium that corresponds to Ka1. H+(aq)+NO−2(aq)⇌HNO2(aq)2. HNO2(aq)⇌H+(aq)+NO−2(aq)3. HNO2(aq)⇌H−(aq)+NO+2(aq)4. HNO2(aq)+H+(aq)⇌H2NO+2(aq)5. HNO2(aq)+H−(aq)⇌H2NO+2(aq)b. By using the value of Ka , calculate ΔG∘ for the dissociation of nitrous acid in aqueous solution. c. What is the value of ΔG at equilibrium? d. What is the value of ΔG when [H+] = 5.9×10−2 M , [NO−2] = 6.7×10−4 M , and [HNO2] = 0.21 M ?
Answers and Explanation:
a)- The chemical equation for the corresponden equilibrium of Ka1 is:
2. HNO2(aq)⇌H+(aq)+NO−2
Because Ka1 correspond to a dissociation equilibrium. Nitrous acid (HNO₂) losses a proton (H⁺) and gives the monovalent anion NO₂⁻.
b)- The relation between Ka and the free energy change (ΔG) is given by the following equation:
ΔG= ΔGº + RT ln Q
Where T is the temperature (T= 25ºc= 298 K) and R is the gases constant (8.314 J/K.mol)
At the equilibrium: ΔG=0 and Q= Ka. So, we can calculate ΔGº by introducing the value of Ka:
⇒ 0 = ΔGº + RT ln Ka
ΔGº= - RT ln Ka
ΔGº= -8.314 J/K.mol x 298 K x ln (4.5 10⁻⁴)
ΔGº= 19092.8 J/mol
c)- According to the previous demonstation, at equilibrium ΔG= 0.
d)- In a non-equilibrium condition, we have Q which is calculated with the concentrations of products and reactions in a non equilibrium state:
ΔG= ΔGº + RT ln Q
Q= ((H⁺) (NO₂⁻))/(HNO₂)
Q= ( (5.9 10⁻² M) x (6.7 10⁻⁴ M) ) / (0.21 M)
Q= 1.88 10⁻⁴
We know that ΔGº= 19092.8 J/mol, so:
ΔG= ΔGº + RT ln Q
ΔG= 19092.8 J/mol + (8.314 J/K.mol x 298 K x ln (1.88 10⁻⁴)
ΔG= -2162.4 J/mol
Notice that ΔG<0, so the process is spontaneous in that direction.
HNO2 is a weak acid whose dissociation occurs as follows; HNO2 (aq) ⇋ H+ (aq) + NO2- (aq)
The equation for the dissociation of HNO2 is;
HNO2 (aq) ⇋ H+ (aq) + NO2- (aq)
We can use the value of Ka to find the ΔG∘ for the dissociation of nitrous acid in aqueous solution as follows;
ΔG∘ = -RTlnKa
Where;
R = Gas constant = 8.314 J/K. mol
Ka = Acid dissociation constant = 4.5×10^−4
T = temperature = 25 ∘C or 298 K
Substituting values;
ΔG∘ = -(8.314 J/K. mol × 298 K × ln 4.5×10^−4)
ΔG∘ = 19.1 KJ/mol
Given that;
Q = [ H+] [NO2- ]/[HNO2]
[ H+] = 5.9×10−2 M
[NO2- ] = 6.7×10−4 M
[HNO2] = 0.21 M
Q = [5.9×10−2 M] [6.7×10−4 M]/[0.21 M]
Q = 1.88 × 10^−4
From the formula;
ΔG = ΔG∘ + RTlnQ
ΔG = 19.1 KJ/mol + (8.314 J/K. mol × 298 K × ln 1.88 × 10^−4)
ΔG = -2.15 KJ/mol
Learn more: https://brainly.com/question/13155407
Question 22 A mixture of krypton and argon gas is expanded from a volume of 33.0L to a volume of 61.0L , while the pressure is held constant at 58.0atm . Calculate the work done on the gas mixture. Be sure your answer has the correct sign (positive or negative) and the correct number of significant digits.
Answer : The work done on the gas mixture is -164 kJ
Explanation :
Formula used :
[tex]w=-p\Delta V\\\\w=-p(V_2-V_1)[/tex]
where,
w = work done = ?
p = pressure of the gas = 58.0 atm
[tex]V_1[/tex] = initial volume = 33.0 L
[tex]V_2[/tex] = final volume = 61.0 L
Now put all the given values in the above formula, we get:
[tex]w=-p(V_2-V_1)[/tex]
[tex]w=-(58.0atm)\times (61.0-33.0)L[/tex]
[tex]w=-1624L.atm=-1624\times 101.3J=-164511.2J=-164.5kJ\aprrox -164kJ[/tex]
conversion used : (1 L.atm = 101.3 J)
Therefore, the work done on the gas mixture is -164 kJ
100 mL of a 1 M HCL and 100 mL of a 5M NaCl solution are mixed. What is the final molarity of the chloride ions?
A.) .5M
B.) 2M
C.) 3M
D.) 4M
Answer:
3M
Explanation:
Because HCl and NaCl do not react with each other, the final number of the Cl⁻ ions is equal to the sum of the ions of each starting reagent:
HCl → H⁺ + Cl⁻Cl⁻ moles from HCl ⇒0.100 L * 1 M = 0.1 moles Cl⁻
NaCl → Na⁺ + Cl⁻Cl⁻ moles from HCl ⇒0.100 L * 5 M = 0.5 moles Cl⁻
Total Cl⁻ moles = 0.1 + 0.5 = 0.6 moles Cl⁻We add up the volumes from each solution:
Final volume = 0.1 L + 0.1 L = 0.2 LAnd finally calculate the final molarity of Cl⁻ ions:
Final molarity = 0.6 mol / 0.2 L = 3MWhich of the following statements about the kinetic molecular theory are not correct?
A. The combined volume of all the molecules of the gas is negligible relative to the total volume in which the gas is contained
B. Gases consist of molecules that are in continuous, random motion
C. The average kinetic energy of the molecules is not related to the absolute temperature
D. Attractive and repulsive forces between gas molecules are negligible
Answer:
The false statement is: (C) The average kinetic energy of the molecules is not related to the absolute temperature
Explanation:
According to the Kinetic Theory of Gases, gases are composed of small fast moving particles that are in constant random motion. These gaseous particles are known as molecules.
It is assumed that the mass of all the gaseous molecules is the same and the intermolecular interactions (attractive or repulsive) are negligible.
Also, the total volume of all the gaseous molecules is considered to be negligible as compared to the volume of the container.
According to this theory, average kinetic energy (K) of the gaseous particles is directly proportional to the absolute temperature (T) of the gas, by the equation:
[tex]K = \frac{3}{2}k_{b}T[/tex]
Here, [tex]k_{b}[/tex] is the Boltzmann constant
Therefore, the false statement about the kinetic molecular theory is (C)
Statement C, which suggests that the average kinetic energy of the molecules is not related to the absolute temperature, is incorrect.
Explanation:The question is focused on the Kinetic Molecular Theory, which primarily has four postulates that describe the behavior of gases. The incorrect statement in the list is the following:
The average kinetic energy of the molecules is not related to the absolute temperatureIn reality, according to the Kinetic Molecular Theory, the average kinetic energy of gas particles is directly proportional to the absolute temperature. This means that as the temperature increases, the average kinetic energy of the gas particles also increases, and vice versa. Therefore, it's clear that the temperature and average kinetic energy are related, making statement C incorrect.
Learn more about Kinetic Molecular Theory here:https://brainly.com/question/15013597
#SPJ11
What is the coordination number for each of the following complexes?A) [Fe(gly)2(H2O)2]+B) [Pb(EDTA)]2−C) [Pt(NH3)4]2+D) Na[Au(CN)2]
Answer:
A) 6
B) 6
C) 4
E) 1
Explanation:
Coordination number, also called Ligancy, the number of atoms, ions, or molecules bound to the metal atom in a complex ion
A) [Fe(gly)2(H2O)2]
Gly = the aminoacid glycin, and works as a bidentate ligand,Bidentate ligands bind through two donor sites. Bidentate means "two-toothed". It can bind to a metal via two donor atoms at once.
This makes the coordination number = 6
B) [Pb(EDTA)]2
EDTA is a hexadentate ligand and forms very stable complexes.
EDTA forms 6 bonds to the Pb atom (2 Pb-N bonds and 4 Pb-O bonds). The coordination number = 6.
C) [Pt(NH3)4]2+
It's a squareplanar complex with coordination number = 4 because 4 bindings with NH3
D) Na[Au(CN)2]
Cyanide binds only to 1 Au- atom. The coordination number = 1
A) [tex][Fe(gly)2(H2O)_2]^+[/tex]: Coordination number is 6.
B)[tex][Pb(EDTA)]_2[/tex]−: Coordination number is 6.
C) [tex][Pt(NH_3)_4]^2+[/tex]: Coordination number is 4.
D) [tex]Na[Au(CN)_2]:[/tex] Coordination number is 2.
The coordination numbers for each of the given complexes are as follows:
A) [tex][Fe(gly)2(H2O)2]+[/tex]: The coordination number of the iron (Fe) ion in this complex is 6. This is because there are two glycine (gly) ligands and two water (H2O) molecules coordinated to the iron ion. Each glycine is bidentate, meaning it binds to the iron ion with two donor atoms (usually nitrogen and oxygen), contributing a total of four donor atoms. The two water molecules each provide one donor atom (oxygen). Thus, the total number of donor atoms around the iron ion is 6, giving it a coordination number of 6.
B) [tex][Pb(EDTA)]2[/tex]: The coordination number of the lead (Pb) ion in this complex is 6. Ethylenediaminetetraacetic acid (EDTA) is a hexadentate ligand, meaning it can bind to a metal ion with all six of its donor atoms (four oxygens and two nitrogens). Since EDTA is fully deprotonated in this complex, it forms a negatively charged species that can wrap around the lead ion, resulting in a coordination number of 6.
C) [tex][Pt(NH_3)_4]^2+:[/tex] The coordination number of the platinum (Pt) ion in this complex is 4. There are four ammonia (NH3) molecules coordinated to the platinum ion, each acting as a monodentate ligand and providing one donor atom (nitrogen). Therefore, the platinum ion is surrounded by four donor atoms, giving it a coordination number of 4.
D) [tex]Na[Au(CN)_2][/tex]: The coordination number of the gold (Au) ion in this complex is 2. There are two cyanide (CN) ligands coordinated to the gold ion, each acting as a monodentate ligand and providing one donor atom (carbon). Thus, the gold ion is surrounded by two donor atoms, giving it a coordination number of 2.
To summarize:
A) [tex][Fe(gly)2(H2O)_2]^+[/tex]: Coordination number is 6.
B)[tex][Pb(EDTA)]_2[/tex]−: Coordination number is 6.
C) [tex][Pt(NH_3)_4]^2+[/tex]: Coordination number is 4.
D) [tex]Na[Au(CN)_2]:[/tex] Coordination number is 2.