At equilibrium, the pH of the solution is 3.48; [H2A] = 0.0496 and [A2-] = 8.2 × 10^-9 M
First ionizationH2A <----> H+ + HA- ;Ka1 = 2.2 × 10^-6
Ka1 = 2.2x10^-6 = [H+][HA-]/[H2A]
At equilibrium:
[H+] = X[HA-] = X[H2A] = 0.05 - XSubstituting in the equation of Ka1
2.2 × 10^-6 = X^2/0.050 - X
Assuming X is small relative to 0.050, 0.050 - X simplifies to 0.050X^2 = 1.1 × 10^-7
X = 3.31 × 10^-4
Since Ka1 <<< Ka2 and [H+] = X
[H+] = 3.31 × 10^-4
pH = - log 3.31 × 10^-4
pH = 3.48
Equilibrium concentration of H2A[H2A] = 0.05 - 3.31 × 10^-4
[H2A] = 0.0496
Second ionization:HA- <------> H+ + A- Ka2 = 8.2 × 10^-9
Ka2 = 8.2 × 10^-9 = [H+][A2-]/[HA-]
HA- ------> H+ + A2-
3.31 × 10^-4 3.31 × 10^-4 0 Initial
-y +y +y Change
{3.31 ×10^-4 -y} {3.31 x10^-4+y} {+y} Equilibrium
Assuming y is very small:
{3.31 ×10^-4 - y} simplifies to 3.31 ×10^-4 {3.31 ×10^-4 + y} simplifies to 3.31 ×10^-4Substituting in the equation of Ka2
8.2 × 10^-9 = (3.31x10^-4) × y /3.31 ×10^-4
y = 8.2 × 10^-9
Equilibrium concentration of A2-Since [A2-] = y
[A2-] = 8.2 × 10^-9 M
Therefore, at equilibrium, the pH of the solution is 3.48; [H2A] = 0.0496 and [A2-] = 8.2 × 10^-9 M
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A cell is put into a liquid and remains its original size. What is the best conclusion that can be drawn from this observation? The concentration of water is higher in the cell than in the liquid, so water is leaving the cell. The concentration of water is higher in the cell than in the liquid, so water is moving in and out of the cell at the same rate. The concentration of water in the cell is the same as in the liquid, so water is moving in and out of the cell at the same rate. The concentration of water in the cell is the same as in the liquid, so water is leaving the cell.
Answer:
The concentration of water in the cell is the same as in the liquid, so water is moving in and out of the cell at the same rate.
Explanation:
The cell is essentially placed in an isotonic solution. In an isotonic solution the concentration of water inside the cell is the same as the outside, causing no water to flow in and out of the cell and keeping the size of the cell intact. In a hypertonic solution the concentration of water inside the cell is higher than the outside, causing water to flow out of the cell and shrinking the cell. In a hypotonic solution the concentration of water inside the cell is lower than the outside, causing water to flow in of the cell and making the cell turgid.
Which one has the greatest number of atoms? 1. all have the same number of atoms 2. 3.05 moles of water 3. 3.05 moles of krypton 4. 3.05 moles of neon 5. 3.05 moles of nh3?
The greatest number of atoms is found in 3.05 moles of ammonia (NH₃) because, with one nitrogen and three hydrogen atoms per molecule, it results in a total of 12.20 moles of atoms. Water (H₂O) would come second with 9.15 moles of total atoms. Single-element samples like krypton and neon only have 3.05 moles of atoms since they are monatomic.
The question of which sample has the greatest number of atoms can be determined by understanding the concept of moles in chemistry. One mole of any substance contains Avogadro's number of entities, which is approximately 6.022 * 10²³. In this case, whether we have 3.05 moles of water (H₂O), krypton (Kr), neon (Ne), or ammonia (NH₃), each mole of any of these substances would have the same number of molecules or atoms.
However, when we are looking for the total number of atoms, for compounds such as water and ammonia which are made up of multiple atoms, the total number of atoms is higher compared to elements like krypton and neon which are atomic. Thus, water, which has three atoms per molecule (two hydrogens and one oxygen), and ammonia, which has four atoms per molecule (one nitrogen and three hydrogens), would have more total atoms when compared with a single atom of krypton or neon per mole
Since 3.05 moles of ammonia (NH3) consist of 1 nitrogen atom and 3 hydrogen atoms per molecule, the total would be 3.05 moles * 4 atoms/molecule = 12.20 moles of atoms. The same calculation for water would give us 3.05 moles * 3 atoms/molecule = 9.15 moles of atoms. Therefore, 3.05 moles of ammonia have the greatest number of atoms.
The passage refers to solutions as homogeneous mixtures. what is the best definition of a homogeneous mixture?
a.a mixture that is uniform throughout
b.a mixture of large particles in a medium that will settle
c.a mixture of particles that remains suspended in a medium
d.a mixture in which the components are easily distinguishable
For a particular redox reaction ClO2– is oxidized to ClO4– and Fe3 is reduced to Fe2 . Complete and balance the equation for this reaction in basic solution. Phases are optional.
Please HELP, I don't know how to balance redox reactions in basic solutions...!
Which is not used in integrated pest management?
A. synthetic pesticides
B. bacteria
C. natural ladybugs
D. viruses
A reaction has the following values. Calculate ΔG.
ΔH = -85.5 kJ/mole ΔS = 0.133 kJ/mole.K) Temperature = 110 ºC
1. -35 kJ
2. -64 kJ
3. -86 kJ
4. -136 kJ
Final answer:
To calculate ΔG, we use the equation ΔG = ΔH - TΔS, converting temperature to Kelvin and substituting the given values. The calculation gives a ΔG of approximately -136.47945 kJ/mol, so the closest answer is -136 kJ.
Explanation:
To calculate the change in Gibbs free energy (ΔG), we can use the Gibbs free energy equation:
ΔG = ΔH - TΔS
First, convert the temperature from Celsius to Kelvin:
T(K) = T(°C) + 273.15 = 110 °C + 273.15 = 383.15 K
Then substitute the given values into the equation:
ΔH = -85.5 kJ/mol
ΔS = 0.133 kJ/(mol)·K
T = 383.15 K
ΔG = (-85.5 kJ/mol) - (383.15 K)(0.133 kJ/(mol)·K)
ΔG = -85.5 kJ/mol - (50.97945 kJ/mol)
ΔG = -136.47945 kJ/mol
The closest answer to ΔG is option 4, -136 kJ.
Acid strength in a series of h−a molecules increases with increasing size of
a. acid strength in a series of molecules increases with increasing size of .
a. True
b. False
The statement that acid strength in a series of H-A molecules increases with increasing size of A is True because the strength of the bond decreases.
What is effect of the size of A on the strength of acid HA?The strength of an acid is related to the strength of the bond between the hydrogen atom and the negative atom.
Increasing the size of A in an acid HA will increase the acid strength because as size increases, the H-A bond will become weaker as the atoms will be farther apart.
The ability to release H⁺ ions will increase as the H-A bond becomes weaker.
Therefore, the statement that acid strength in a series of H-A molecules increases with increasing size of A is True because the strength of the bond decreases.
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What is a rocky part of the shore that sticks out in th ocean
Increasing the total pressure above a liquid raises the boiling point. Which of the following best explains why?
Do all molecules contain only single bonds
Answer: The given statement is false.
Explanation:
A single bond is defined as the bond through which two same or different atoms are combined to each other by a single line. It is represented by a hyphen.
For example, C-H shows that both carbon and hydrogen atoms are attached to each other through single bond.
It is not necessary that all the molecules contain a single bond. This is because there are molecules which contain a double or triple bond also.
For example, [tex]H_{2}C=CH_{2}[/tex] is ethene molecule and it contains a double bond.
Therefore, we can conclude that the statement all molecules contain only single bond, is false.
Water vapor in the earth's air is an example of a solution. what type of solution would this be
Answer:
gas in a gas
Explanation:
Because it is water VAPOR and not LIQUID water, it would be a gas in a gas. :)
Final answer:
Water vapor in the earth's air is a gaseous solution, where air acts as the solvent and water vapor is the solute. Water vapor plays a key role as a greenhouse gas and in the formation of clouds and precipitation, impacting the Earth's climate and weather patterns.
Explanation:
Water vapor in the earth's air is indeed an example of a solution, specifically, it is a gaseous solution. In this context, the air can be thought of as the solvent, and the water vapor as the solute. Starting with a basic understanding that air is a solution where nitrogen is the primary solvent, it is easy to then categorize the mixture of air and water vapor accordingly.
The Earth's atmosphere contains varying amounts of water vapor, which is crucial for climate and weather phenomena. It can range from less than one percent in the coldest environments to more than four percent in the warmest, humid air. Water vapor can act as a greenhouse gas, absorbing Earth's outgoing long-wave radiation, which influences the temperature of our planet. In the form of clouds, which are formed by water vapor condensing around condensation nuclei, water vapor also contributes to the Earth's albedo by reflecting incoming solar radiation. Whether in the form of vapor or condensed into clouds or precipitation, water plays a key role in atmospheric processes.
1. The IMA of the doorknob shown is .
1
0.2
6
2. What is the IMA of the inclined plane shown?
6
6.75
3
3. Choose the mathematical formula expressing work.
W=F x d
W=d/F
W=F/d
Explanation :
(a) The full form of IMA is Ideal Mechanical Advantage. It is given as the ratio of the radius of the wheel and the radius of the axle.
From the figure,
The radius of the wheel is 6 cm
and the radius of the axle is 1 cm.
[tex]IMA=\dfrac{6\ cm}{1\ cm}=6\ cm[/tex]
So, the IMA of the doorknob is 6.
(b) The IMA of the inclined plane is given by the ratio of the distance covered by the effort (L) and the distance covered by the resistance (h).
So, [tex]IMA=\dfrac{4.5\ m}{1.5\ m}=3[/tex]
So, the IMA of the inclined plane is 3.
(c) Work done is the product of the force acting and the displacement caused.
Mathematically, it can be written as :
[tex]W=F\times d[/tex]
F is applied force
d is the distance or displacement.
Jason-1 was launched to:
measure ocean waves
determine air moisture
survey ocean currents
all of the above
Answer: survey ocean currents
The correct answer will be option- all of the above.
Explanation:
Jason or "Joint Altimetry Satellite Oceanography Network" is the satellite sent under the joint mission between NASA and CNES in France.
The satellite worked from 2001 to 2005 which was succeeded by Jason-2 in 2008.
The main aim of this was to measure climate change by measuring the valleys and hills of the ocean's surface. This helped to determine the direction of the ocean currents and global ocean circulation. This also helped the determine the air moisture.
Thus, All of the above is the correct answer.
An atom of an element with two valence electrons reacts with two atoms of an element with atomic number 17 to form an ionic compound. What is the compound MOST LIKELY formed as described? A) CaF2 B) MgCl2 C) CO2 D) BeBr2
Answer is: B) MgCl2.
Chlorine has atomic number 17, it means it has 17 protons and 17 electrons.
Electron configuration of chlorine atom: ₁₇Cl 1s² 2s² 2p⁶ 3s² 3p⁵.
Chloride is negative ion of chlorine. Chloride is formed when chlorine gain one lectron.
Chloride anion has 17 protons and 18 electrons (like argon-noble gas).
The electron configuration for the chloride ion: ₁₇Cl⁻ 1s²2s²2p⁶3s²3p⁶.
Magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number.
Magnesium is metal from second group of Periodic table of elements and it lost two electrons to have electron configuration as closest noble gas neon (₁₀Ne), chlorine is nonmetal from 17. group of Periodic table and it gains one electron to have electron configuration as argon (₁₈Ar).
The source of Earth's magnetic field is _____. solid magnetized iron in the core liquid magnetized iron in the core liquid iron in the core liquid metallic hydrogen in the core
The answer is liquid iron in the core. As the liquid iron churns, due to convection currents and Coriolis effect of the earth’s spin, in the inner core of the earth. The iron molecules/atoms, which are in charged particle form due to the high temperatures, move become akin to an electric current and produce magnetic fields. These magnetic fields cause increases electric currents in the core as a result of induction. This produces even more powerful magnetic fields that span the outer space.
Answer:
liquid iron in the core
Explanation:
God BLESS
Calculate the molality of a solution prepared by dissolving 175 g of KNO3 in 750 g of water. (round to nearest hundreth)
Answer:
2.31 molar
Explanation:
175 g/101 g/mol=1.73 mol
1.73mol/.750 L = 2.31 mol/L
Determine the [oh−] of a solution that is 0.125 m in co32−.
Final answer:
To estimate the concentration of hydroxide ions ([OH-]) in a 0.125 M carbonate (CO3²-) solution, we would simply use the stoichiometry assuming that each carbonate ion becomes one hydroxide ion, giving an approximate [OH-] value of 0.250 M. This is a simplification and actual values may vary according to equilibrium dynamics.
Explanation:
To determine the concentration of hydroxide ions ([OH-]) in a solution that is 0.125 M in carbonate ions (CO32-), we need to understand the relationship between carbonate and hydroxide ions in an aqueous solution. Carbonate ions can react with water in a basic reaction to form bicarbonate ions (HCO3-) and hydroxide ions (OH-).
In this reaction, each carbonate ion can produce two hydroxide ions. Therefore, if we have a 0.125 M solution of carbonate ions, we could potentially have a hydroxide concentration of 0.125 M × 2 = 0.250 M. But, since this is a basic reaction and not all carbonate will turn into hydroxide ions (due to equilibrium with bicarbonate), we need additional information to calculate the exact hydroxide concentration, such as the equilibrium constant for the reaction.
However, without this information, we can assume a 1:1 stoichiometry for simplicity, giving us an initial approximate [OH-] concentration of 0.250 M. This is a simplification and the actual concentration could be less due to the reasons stated above.
For more accurate results, we would use the equilibrium constant for the reaction between carbonate and water to calculate the exact [OH-].
All organisms use oxidation-reduction reactions to harness energy, and this newly harvested energy is used to produce atp. oxidation is defined as the loss of electrons. reduction is the gain of electrons. the energy in fuel molecules (often carbohydrates) is in the form of electrons. when electrons are removed from their high-energy state in fuel molecules (the electron donors), those molecules are oxidized. the electrons must be added to another molecule, which serves as the electron acceptor. as it gains electrons, the electron acceptor is reduced. when these electrons arrive at the final electron acceptor, they are at a lower-energy state compared to their original position in the electron donor. the goal is to harness the energy the electrons lose during this transfer process. in this activity, you will examine three equations and indicate which reactants are electron donors and which are receptors. in addition, you will identify the oxidized product and the reduced product
Which type of chemical reaction occurs in C6H12 + 9O2 mc031-1.jpg 6CO2 + 6H2O? synthesis combustion single replacement double replacement
Combustion- is the correct answer on E.D.G
Answer:
B. COMBUSTION
Explanation:
just took test on edge 2020
What is the boiling point of a solution made by mixing 75.0g ZnCl2 with 375.0 grams of water? (Kb for water is 0.512 C/m)
Final answer:
The boiling point of a solution made by mixing ZnCl2 with water can be calculated using the boiling point elevation formula. In this case, the boiling point of the solution is approximately 100.707°C.
Explanation:
Boiling point elevation formula: ΔTb = iKbm
Given: Mass of ZnCl2 = 75.0g, mass of water = 375.0g, Kb for water = 0.512°C/m, i = 2 (for ZnCl2)
Calculations: ΔTb = 2 * 0.512 * (75.0/136.30) = 0.707°C
Boiling point of solution: 100.0°C + 0.707°C = 100.707°C
how many grams of ammonia would be formed from the complete reaction of 4.50 moles hydrogen
Answer:
51 grams of ammonia would be formed.
Explanation:
[tex]3H_2+N_2\rightarrow 2NH_3[/tex]
Moles of hydrogen gas = 4.50 moles
According to reaction, 3 moles of hydrogen gas gives 2 moles of ammonia gas.
Then 4.50 moles of hydrogen gas will give:
[tex]\frac{2}{3}\times 4.50 mol=3.00 mol[/tex]of ammonia
Mass of 3.00 moles of ammonia:
[tex]17 g/mol\times mol=51 g[/tex]
51 grams of ammonia would be formed.
Final answer:
To find out how many grams of ammonia are produced from 4.50 moles of hydrogen, the balanced chemical equation for the synthesis of ammonia and the 3:2 mole ratio between hydrogen and ammonia are used. It is calculated that 4.50 moles of hydrogen will produce 3.00 moles of ammonia which is equivalent to 51.093 grams of ammonia.
Explanation:
To determine how many grams of ammonia would be formed from the complete reaction of 4.50 moles of hydrogen, we must use the balanced chemical equation for the synthesis of ammonia:
N2(g) + 3H2(g) → 2NH3(g)
From the equation, we see that 3 moles of hydrogen gas (H2) produce 2 moles of ammonia (NH3). Hence, the mole ratio is 3 moles H2 to 2 moles NH3. To find the amount of ammonia produced from 4.50 moles of hydrogen, we can set up a ratio:
3 moles H2 : 2 moles NH3 = 4.50 moles H2 : x moles NH3
Calculating this gives us:
4.50 moles H2 / 3 moles H2 * 2 moles NH3 = 3.00 moles NH3
To convert moles of NH3 to grams, we need to know the molar mass of NH3, which is approximately 17.031 g/mol:
3.00 moles NH3 * 17.031 g/mol = 51.093 grams of ammonia.
One kind of radiation not released by radioactive decay is ______
~A~ Free Protons
~B~ Beta Particles
~C~ Gamma Rays
~D~ Alpha Particles
If 30mL of 0.5M KOH is needed to neutralize 2M HCl, what was the volume of the acid?
Magnesium reacts with hydrochloric acid, HCl, to form magnesium chloride and hydrogen gas. The reaction is: Mg + 2HCl → MgCl2 + H2 What is the mass of HCl that would be required to completely react with 5.2 grams of Mg? 6.9 6.934 16 15.60
the answer above is wrong
A giant ball of hot gas mainly hydrogen and helium is
PLEASE HELP ASAP!!!
When silver tarnishes, a _____ reaction happens.
1. combustion
2. decomposition
3. double replacement
4. single replacement
5. synthesis
When silver tarnishes, a single replacement reaction occurs, during which silver is replaced by sulfur atoms, forming silver sulfide and changing the oxidation state of the silver.
Explanation:When silver tarnishes, a single replacement reaction happens. This is because the silver metal reacts with sulfur, commonly found in traces in the air or from certain foods like eggs, and undergoes a reaction where the silver is replaced by sulfur atoms, forming silver sulfide.
During this process, the oxidation state of the silver changes, which is another characteristic of a single replacement reaction. Other possible reaction categories could include synthesis, decomposition, double replacement, and combustion, but these do not accurately describe the tarnishing of silver. In a synthesis reaction, multiple substances combine to form a single new substance, while in decomposition, a single compound breaks down to form multiple new substances. Combustion typically involves a substance reacting with oxygen to produce heat and light.
The tarnishing of silver thus illustrates an oxidation-reduction, or “redox” reaction, encompassing aspects of a single replacement reaction in which the element sulfur replaces the silver in a compound, altering the silver's oxidation state in the process.
Which type of particle retains the identity of an element during a chemical reaction? a) electron
b) proton
c) atom
Atom A has seven electrons in its outer shell. Atom B has one electron in its outer shell. They react and bond. Now both atoms have eight electrons in their outer shells. What kind of bond has formed?
The atom with 7 valence electrons gains one electron from the second atom with one valence electrons will bond together through ionic bonding.
What are ionic compounds ?Ionic compounds are formed between metals and non-metals. The metals are electropositive and easily loss electrons to electron deficient non metals to achieve octet.
When the non-metals gain electrons they acquire a negative charge and metals gain a positive charge by losing electron. These opposite charges electrostatically attracts and form the ionic bond.
The atom with one valence electron will donate it to the atom with 7 valence electrons to achieve octet. The donated atom acquires a positive charge and the received atom gains a negative charge. These ions attracts electrostatically to form the bond.
For example, in NaCl, sodium chloride is an ionic compound formed by donating an electrons from the sodium metal to the Cl atom. Thus, Na becomes Na + and Cl becomes Cl-. Therefore, option c is correct.
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Most earthquakes occur along fractures in the Earth's crust called faults. Most faults occur along the edges of A) continents. B) polar regions. C) tectonic plates. D) mountain ranges.
Most earthquakes occur along fractures in the Earth's crust called faults. Most faults occur along the edges of tectonic plates. . thus option C is correct.
what is earthquake?A sudden release of stress along faults in the earth’s crust can be called as earthquake; the process is like where the tectonic plates move slowly , but they get stuck at their edges due to friction.
When the stress overcomes the friction causes earthquake and the resulting waves propagate through the ground and over its surface generate a shaking that we perceive as earthquakes.
The main causes of earthquakes include Plate tectonics which account for most earthquakes worldwide, Induced quakes caused by human activity, like tunnel construction, Volcanic quakes, Collapse quakes caused by cave-ins, mostly in karst areas.
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Maya, a student, performs a titration. She completes the following steps as part of her titration procedure. 1. She cleans and rinses a burette with base solution. 2. She fills the burette with standardized base solution. 3. She adds a base from a burette to an acid. 4. She observes a color change in the Erlenmeyer flask. 5. She continues to add more base. Based on the above procedure, will she obtain accurate results? Yes, because the more base there is, the better the results will be. No, because she initially contaminated the burette with base. Yes, because she used a standardized base solution in the burette. No, because she did not stop adding base once the color changed.