A buffer of pH 9.24 is to be prepared from a weak acid and its salt. The best acid from which to prepare the buffer is

(A) phthalic acid, K1 = 1.3 x 10-3 (1st ionization)
(B) hydrohen phthalate, K2 = 3.9 x 10-5
(C) arsenious acid, Ka = 6 x 10-10
(D) formic acid, Ka = 1.8 x 10-5
(E) phenol, Ka = 1.3 x 10-10

Answer: The [tex]\Delta H^o_{rxn}[/tex] for the reaction is -521.6 kJ.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The chemical equation for the reaction of fluorine and water follows:

[tex]2F_2(g)+2H_2O(l)\rightarrow 4HF(g)+O_2(g)[/tex]   [tex]\Delta H^o_{rxn}=?[/tex]

The intermediate balanced chemical reaction are:

(1) [tex]H_2(g)+F_2(g)\rightarrow 2HF(g)[/tex]    [tex]\Delta H_1=-546.6kJ[/tex]    ( × 2)

(2) [tex]H_2(g)+O_2(g)\rightarrow 2H_2O(g)[/tex]    [tex]\Delta H_2=-571.6kJ[/tex]

The expression for enthalpy of reaction follows:

[tex]\Delta H^o_{rxn}=[2\times \Delta H_1]+[1\times (-\Delta H_2)][/tex]

Putting values in above equation, we get:

[tex]\Delta H^o_{rxn}=[(2\times (-546.6))+(1\times (571.6))]=-521.6kJ[/tex]

Hence, the [tex]\Delta H^o_{rxn}[/tex] for the reaction is -521.6 kJ.

Answer:

The system does work on the surroundings.

Explanation:

The work (w) exerted in a chemical reaction depends on the change in the number of gaseous moles (Δn(g)), where

Δn(g) = n(gas, products) - n(gas, reactants)

These variables are linked through the following expression.

w = -R.T.Δn(g)

where,

R is the ideal gas constant

T is the absolute temperature

At constant pressure, which of these systems do work on the surroundings?

a. 2A(g) + 3B (g) ------> 4C (g)

Δn(g) = 4 -5 = -1. The surroundings do work on the system.

b. 2A(g) + 2B (g) -------> 5C(g)

Δn(g) = 5 -4 = 1. The system does work on the surroundings.

c. 2A (g) + B (g) -----> C(g)

Δn(g) = 1 - 3 = -2. The surroundings do work on the system.

d. A(s) + B(g) -------> 2C (g)

Δn(g) = 2 -2 = 0. No work is done.

The product of the given reaction, an acid-catalyzed hydration of an alkene, would be 2-butanol, as per Markovnikov's Rule. This rule predicts the placement of the hydrogen and halide groups in a reaction.

The reaction given is an example of an acid-catalyzed hydration of an alkene. In such reactions, an alkene reacts with water in the presence of an acid (in this case, H3PO4) to form an alcohol. The prediction of the product involves recognizing the reaction type and the reagents involved.

For the given reaction: CH3CH=CHCH3 + H2OH3PO4⟶, the product would be 2-butanol.

But why does this process form 2-butanol? It all comes down to Markovnikov's rule, which predicts that in the addition of a protic acid HX to an alkene, the acid hydrogen (H) becomes attached to the carbon with fewer alkyl substituents, and the halide (X) group becomes attached to the carbon with more alkyl substituents.

https://brainly.com/question/30891657

#SPJ11

Answer:

[H3O+] = 0.0117 M

[OH-] = 8.5 * 10^-13 M

Explanation:

Step 1: Data given

Concentration of HCl = 0.0117 M

Step 2:

HCl is a strong acid

pH of a strong acid = -log[H+] = - log[H3O+]

[H3O+] = 0.0117 M

pH = -log(0.0117)

pH = 1.93

pOH =14 - 1.93 = 12.07

pOH = -log[OH+] = 12.07

[OH-] = 10^-12.07 = 8.5 * 10^-13

Or

Kw / [H3O+] = [ OH-]

10^-14 / 0.0117 = 8.5*10^-13

Final answer:

The hydronium ion concentration [H3O+] in a 0.0117 M HCl solution is 0.0117 M, and the hydroxide ion concentration [OH-] is calculated to be 8.55 × 10^-13 M using the water dissociation constant.

Explanation:

To calculate the hydronium ion concentration, [H3O+], of a 0.0117 M HCl solution, we first need to understand that HCl is a strong acid which dissociates completely in water. This means that for every mole of HCl dissolved, there will be one mole of H3O+ ions in solution. Hence, the hydronium ion concentration in a 0.0117 M HCl solution is also 0.0117 M.

As for the hydroxide ion concentration, [OH-], we use the water dissociation constant (Kw), which is 1.0 × 10-14 at 25 °C. The product of the concentrations of the hydronium and hydroxide ions in any aqueous solution is equal to Kw. We can find [OH-] by rearranging the expression Kw = [H3O+][OH-] to solve for [OH-], giving us [OH-] = Kw / [H3O+]. Substituting in the values we get [OH-] = 1.0 × 10-14 M / 0.0117 M = 8.55 × 10-13 M.

Answer:

(a) Ionic

(b) Nonpolar covalent

(c) Polar covalent

(d) Polar covalent

(e) Nonpolar covalent

(f) Polar covalent

For those substances with polar covalent bonds, which has the least polar bond? NO₂

For those substances with polar covalent bonds, which has the most polar bond? BF₃

Explanation:

Are the bonds in each of the following substances ionic, nonpolar covalent, or polar covalent?

The nature of a bond depends on the modulus of the difference of electronegativity (|ΔEN|) between the atoms that form it.

(a) KCl    |ΔEN| = |EN(K) - EN(Cl)| = |0.8 - 3.0| = 2.2. The bond is ionic.

(b) P₄      |ΔEN| = |EN(P) - EN(P)| = |2.1 - 2.1| = 0.0. The bond is nonpolar covalent.

(c) BF₃    |ΔEN| = |EN(B) - EN(F)| = |2.0 - 4.0| = 2.0. The bond is polar covalent.

(d) SO₂   |ΔEN| = |EN(S) - EN(O)| = |2.5 - 3.5| = 1.0. The bond is polar covalent.

(e) Br₂    |ΔEN| = |EN(Br) - EN(Br)| = |2.8 - 2.8| = 0.0. The bond is nonpolar covalent.

(f) NO₂   |ΔEN| = |EN(N) - EN(O)| = |3.0 - 3.5| = 0.5. The bond is polar covalent.

The nature of bonding between atoms depends on the electro negativity between the atoms in the bond.

An ionic bond is formed by transfer of electrons from one atom to another. It commonly occurs between a metal and a nonmetal. Covalent bonds are formed when electrons are shared between bonding atoms. If the electronegativity difference between the two bonding atoms is small, electrons are equally shared in the molecule and the bonds are nonpolar. However, when the difference in electro negativity is significant (about 0.5) a significant magnitude of polarity of the bond is observed and the bond us polar because electrons lie closer to the more electronegative atom.

The classification of the compounds according to nature of bonding between atoms is done as follows;

KCl - ionic bond

P4 - nonpolar covalent bond

BF3 - polar covalent bond

SO2 - polar covalent bond

Br2 - nonpolar covalent

NO2 - polar covalent bond.

The most polar bond occurs between bromine and bromine because of a large electro negativity difference between the both atoms.

Learn more: https://brainly.com/question/17762711

Answer:

To prepare 50L of 32% solution you need: 11L of 30% solution, 22L of 50% solution and 17L of 10% solution.

Explanation:

A 32% solution of acid means 32L of acid per 100L of solution. As the chemist wants to make a solution using twice as much of the 50% solution as of the 30% solution it is possible to write:

2x*50% + x*30% + y*10% = 50L*32%

130x + 10y = 1600 (1)

-Where x are volume of 30% solution, 2x volume of 50% solution and y volume of 10% solution-

Also, it is possible to write a formula using the total volume (50L), thus:

2x + x +y = 50L

3x + y = 50L (2)

If you replace (2) in (1):

130x + 10(50-3x) = 1600

100x + 500 = 1600

100x = 1100

x = 11L -Volume of 30% solution-

2x = 22L -Volume of 50% solution-

50L - 22L - 11L = 17 L -Volume of 10% solution-

I hope it helps!

Final answer:

To create a 50-liter mixture with 32% acid concentration, the chemist should use 20 liters of the 10% acid solution, 10 liters of the 30% acid solution, and 20 liters of the 50% acid solution.

Explanation:

The question involves solving a system of linear equations to determine the volume of each acid solution required to create a 50-liter mixture with a 32% acid concentration. Let's denote the amount of the 10% solution as x liters, the 30% solution as y liters, and the 50% solution as 2y liters (since it's twice the amount of the 30% solution).

The total amount of acid should be 32% of the 50-liter mixture: 0.10x + 0.30y + 0.50(2y) = 0.32 × 50.

We've also established the relationship between the 30% and 50% solutions: 2y is twice the amount of y.

x + 3y = 50

0.10x + 0.30y + 1.00y = 16

Combining and rearranging gives us x = 20 liters, y = 10 liters, and thus 2y = 20 liters. Therefore, to obtain the desired mixture, the chemist should use 20 liters of the 10% solution, 10 liters of the 30% solution, and 20 liters of the 50% solution.

Explanation:

The heat gained by the solution = q

[tex]q=mc\times (T_{final}-T_{initial})[/tex]

where,

q = heat gained = ?

c = specific heat of solution= [tex]4.18 J/^oC[/tex]

Mass of the solution(m) = mass of water + mass of calcium chloride

Mass of water = ?

Volume of water = 50.00 mL

Density of water = 1.00 g/mL

Mass = Density × Volume

m = 1.00 g/mL × 50.00 mL = 50.00 g

Mass of the solution (m) = 50.00 g + 4.51 g =54.51 g

[tex]T_{final}[/tex] = final temperature = [tex]25.8 ^oC[/tex]

[tex]T_{initial}[/tex] = initial temperature = [tex]22.6 ^oC[/tex]

Now put all the given values in the above formula, we get:

[tex]q=54.51 g\times 4.18 J/g^oC\times (25.8-22.6)^oC[/tex]

[tex]q=729.126 J[/tex]

The heat gained by the solution is 729.126 J.

Heat energy released during the reaction  = q'

q' = -q  ( law of conservation of energy)

q' = -729.126 J

The heat energy released during the reaction is -729.126 J.

Moles of calcium chloride, n = [tex]\frac{4.51 g}{111 g/mol}=0.04063 mol[/tex]

[tex]\Delta H_{rxn}=\frac{q'}{n}=\frac{-729.126 J}{0.04063 mol}=-17,945.23 J/mol= -17.945 kJ/mol[/tex]

The ΔH of the reaction is -17.945 kJ/mol.

cis−1−chloro−2−methylcyclohexane undergoes E2 elimination more quickly than its trans isomer due to its axial configuration allowing for an anti-periplanar orientation, which is favorable for E2 elimination.

The E2 elimination reaction of cis−1−chloro−2−methylcyclohexane happens faster than its trans isomer due to the orientation of its reacting groups. In the cis isomer, the leaving group (the chlorine) and the beta-proton are both axial. This axial positioning on the same side of the cyclohexane ring allows for an anti-periplanar orientation, which is favorable for an E2 elimination.

However, for the trans isomer, the beta-proton is equatorial while the leaving group (the chlorine) is axial, preventing them from assuming the anti-periplanar configuration. Hence, it becomes less stable and present in a lower concentration. Because the cis isomer can more readily achieve this favored geometry, it reacts more quickly in E2 reactions.

https://brainly.com/question/38854028

#SPJ2

Answer:

The change in entropy of gas is [tex]\Delta S= nC_{P}ln3[/tex]

Explanation:

n= Number of moles of gas

Change in entropy of gas = [tex]ds= \int \frac{dQ}{T}[/tex]

[tex]dQ= nC_{p}dT[/tex]

From the given,

[tex]V_{i}=V[/tex]

[tex]V_{f}=3V[/tex]

Let "T" be the initial temperature.

[tex]\frac {V_{i}}{T_{i}}=\frac {V_{f}}{T_{f}}[/tex]

[tex]\frac {V}{T}=\frac {3V}{T_{f}}[/tex]

[tex]{T_{f}} = 3T[/tex]

[tex]\int ds = \int ^{T_{f}}_{T_{i}} \frac{nC_{P}dT}{T}[/tex]

[tex]\Delta S = nC_{p}ln(\frac{T_{f}}{T_{i}})[/tex]

[tex]\Delta S = nC_{p}ln3[/tex]

Therefore, The change in entropy of gas is [tex]\Delta S= nC_{P}ln3[/tex]

Answer:

Percentage of uncertainty in average speed of an electron is 0.1756%.

Explanation:

Using Heisenberg uncertainty principle:

[tex]\Deltax\times \Delta p\geq \frac{h}{4\pi }[/tex]

[tex]\Delta p=m\times \Delta v[/tex]

[tex]\Deltax\times m\times \Delta v\geq \frac{h}{4\pi }[/tex]

Δx = Uncertainty in position

Δp = Uncertainty in momentum

Δv = Uncertainty in average speed

h = Planck's constant = [tex]6.626\times 10^{-34} kg m^2/s[/tex]

m = mass of electron =  [tex]9.1\times 10^{-31} kg[/tex]

We have

Δx = 2 × 165 pm = 330 pm = [tex]3.3\times 10^{-10} m [/tex]

[tex]1 pm = 10^{-12} m[/tex]

Average orbital speed of electron = v = [tex]=1.0\times 10^8 m/s[/tex]

[tex]3.3\times 10^{-10} 9.1\times 10^{-31} kg \times \Delta v\geq \frac{6.626\times 10^{-34} kg m^2/s}{4\pi }[/tex]

[tex]\Delta v\geq \frac{6.626\times 10^{-34} kg m^2/s}{4\pi \times 3.3\times 10^{-10}\times 9.1\times 10^{-31} kg}[/tex]

[tex]\Delta v\geq 1.756\times 10^5 m/s[/tex]

Percentage of uncertainty in average speed:

[tex]=\frac{\Delta v}{v}\times 100[/tex]

[tex]=\frac{1.756\times 10^5 m/s}{1.0\times 10^8 m/s}\times 100=0.1756\%[/tex]

Answer:

-4.30 × 10³ kcal

Explanation:

Let's consider the following thermochemical equation for the combustion of acetone.

C₃H₆O(l) + 4 O₂ (g) → 3 CO₂(g) + 3 H₂O(g) ΔH°of the reaction = -1790 kcal

When 1 mole of C₃H₆O burns, 1790 kcal of heat are released. We have to find out how many moles of C₃H₆O reacted in 177 mL. Considering the density of acetone is 0.788 g/mL and its molar mass is 58.08 g/mol, the moles of acetone are:

[tex]177mL.\frac{0.788g}{mL} .\frac{1mol}{58.08g} =2.40mol[/tex]

The heat released when 2.40 moles of acetone burn is:

[tex]2.40mol.\frac{(-1790kcal)}{1mol} =-4.30 \times 10^{3} kcal[/tex]

Answer:

0.443 g

Explanation:

In the electrolysis of an aqueous solution of NaCl, the following half-reactions take place:

Reduction: Na⁺(aq) + 1 e⁻ ⇒ Na(s)

Oxidation: 2 Cl⁻(aq) ⇒ Cl₂(g) + 2 e⁻

Let's consider the following relations:

Suppose a current of 18.0 A is passed through an aqueous solution of NaCl for 67.0 seconds. The mass of chlorine produced is:

[tex]67.0s.\frac{18.0c}{s} .\frac{1mole^{-} }{96468c} .\frac{1molCl_{2}}{2mole^{-} } .\frac{70.9gCl_{2}}{1molCl_{2}} =0.443gCl_{2}[/tex]

Using Faraday's law of electrolysis, we can calculate the mass of chlorine produced by an 18.0 A current over 67.0 seconds in the chlor-alkali process. The result is approximately 0.44 grams.

To determine the mass of chlorine produced in the chlor-alkali process using a current of 18.0 A for a duration of 67.0 seconds, we need to use Faraday's law of electrolysis. This states that the amount of a substance produced at an electrode during electrolysis is directly proportional to the quantity of electricity that passes through the solution.

The amount of a substance produced can be calculated using the formula: It = zF, where I is the current in amperes, t is the time in seconds, z is the ionic charge(1 for Cl-), and F is Faraday’s constant (96500 coulombs per mole of electrons).

First, let’s find the quantity of electric charge (Q) that has passed through the solution using the formula Q = It. In this case, I = 18 A and t = 67.0 seconds, so Q = 18 * 67.0 = 1206 Coulombs.  

Now we can use this Q in the formula of m = QM/zF, where M is the molar mass of chlorine, which is approximately 35.5 g/mol. After plugging the numbers in, we find the mass (m) of the chlorine produced is 0.44 g.

https://brainly.com/question/30343167

#SPJ11

Ansfdfggggggggggggggggggggggggggggghhhhhhhhhhhhhhhhhkkkkkkkkkkkkkkkkkkvvvvvvvvvvvvvvvgggggggggggg

Explanation:

Answer:

To calculate the molar mass add the atomic mass of each atom in the chemical formula.

Explanation:

For example Molar mass of NaHCO₃  calculated as

Molar mass is the sum of masses of all atom present in formula.

Atomic mass of sodium = 23 g/mol

Atomic mass of hydrogen = 1.008 g/mol

Atomic mass of carbon = 12 g/mol

Atomic mas of Oxygen = 16 g/mol

Molar mass of NaHCO₃ = 23 + 1.008 + 12 + 16× 3

Molar mass of NaHCO₃ = 23 + 1.008 + 12 + 48

Molar mass of NaHCO₃ = 84.008 g/mol

Answer:

C.) A molecular solid

Explanation:

Molecular solids have low melting points, are non-conductive and are insoluble in water. The interactions between the molecules or atoms can be hydrogen bonds, dipole dipole or London dispersion forces.Because they have relatively weak bonds there are easily vaporized and therefore have a low melting point. Although a network covalent solid is non-conductive it has a high melting point due to the strong covalent bonds. The metallic and the ionic solids are both conductive, with the metallic solids having a high melting point.

A substance that is nonconductive, with a low melting point, and insoluble in water is most likely a molecular solid, due to its weak intermolecular forces and neutral molecular composition.

The substance described as nonconductive, having a relatively low melting point, and insoluble in water is most likely C.) A molecular solid. Molecular solids are typically composed of molecules held together by relatively weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds. These characteristics result in their low melting points and the inability to conduct electricity. Since they are made up of neutral molecules, they usually do not dissolve in water which is a polar solvent. On the other hand, metallic solids conduct electricity and are malleable, ionic solids conduct electricity when molten and are usually water soluble, and network covalent solids are typically hard and have high melting points.

Answer:

The partial pressure of krypton in the flask is 0.59 atm and the total pressure in the flask is 1.39 atm

Explanation:

This must be solved with the Ideal Gas Law equation.

First of all we need the moles or Ar and Kr in the mixture

Moles = Mass / Molar mass

Molar mass Ar 39.95g/m

Moles Ar = 6.18 g/39.95 g/m → 0.154 moles

Molar mass Kr 83.8 g/m

Moles Kr = 9.66 g/ 83.8g/m → 0.115 moles

Total moles in the mixture: 0.154 moles + 0.115 moles = 0.269moles

Now, we have the total moles, we can calculate the total pressure.

P . V = n . R . T

(T° in K = T° in C + 273)

P. 5.38L = 0.269mol . 0.082 L.atm/mol.K . 340K

P = (0.269mol . 0.082 L.atm/mol.K . 340K) / 5.38 L

P = 1.39 atm

Now we have the total pressure, we can apply molar fraction so we can know the partial pressure of Kr.

Kr pressure / Total Pressure = Kr moles / Total moles

Kr pressure / 1.39 atm = 0.115 moles / 0.269 moles

Kr pressure = (0.115 moles / 0.269 moles) / 1.39atm

Kr pressure = 0.59 atm

When a chlorine atom attracts an electron from sodium, the sodium atom becomes positively charged, forming a sodium cation with a +1 charge, while chlorine becomes a chloride ion with a -1 charge, resulting in the formation of NaCl.

If a chlorine atom were to attract an electron from sodium, the sodium atom would become positively charged. This occurs because chlorine has a high affinity for electrons due to its seven valence electrons, and it is more energy-efficient for chlorine to gain one electron than to lose seven. When chlorine gains an extra electron, it becomes a chloride ion with a net negative charge. Conversely, when sodium loses its single valence electron, it becomes a sodium ion with a +1 charge, also known as a cation.

The transfer of an electron from sodium to chlorine results in the formation of two oppositely charged ions that are held together by an ionic bond, creating the ionic compound NaCl. This electron transfer satisfies the octet rule for both ions, resulting in complete outermost shells with stable electron configurations.

Answer:

In the Lewis structure of P4 there are 6 bonding pairs and 4 lone pairs of electrons.

Explanation:

The structure of tetrahedral molecule of P4 is provided below.

Each phosphorus atom has 5 valence electrons out of which 3 electrons involve in bonding and the rest 2 electrons exist as a lone pair that does not involve in bonding.Hence each phosphorus atom has one lone pair.In P4 molecule there are phosphorus atoms and hence 4 lone pairs in total.

As you can see in the figure, each phosphorus atom is bonded to the other three atoms.A bond is formed when two atoms share one electron each and the pair is called bonding pair.

From the figure we can see that there are 6 bonds in total.Each bond consist of one bonding pair of electrons and hence in total there are 6 bonding pairs of electrons.

Hence in a P4 molecule there are six bonding pairs and 4 lone pairs of electrons.

Answer:

D.) sp² and sp³

Explanation:

Acetic acid  CH₃COOH

H3C-----sp³                        C(O)OH----sp²

Answer:

a,c are correct

Explanation:

a) On mixing two gases the final temperature of both the gases becomes the same. The heat will flow from high temp. gas to lower temp gas till the temp of both gases become equal (Thermal equilibrium). This is correct.

b) The rms speed of the molecule is inversely proportional to its molar mass so the final rsm will not be the same. This is incorrect.

c) The average kinetic energy of the system will remain the same. Hence this is also correct.

Answer:

3 Fe₂O₃(s) + H₂(g) ⇒ 2 Fe₃O₄(s) + H₂O(g)    ΔH° = -6.00 kJ

Explanation:

Let's consider the following balanced equation.

3 Fe₂O₃(s) + H₂(g) ⇒ 2 Fe₃O₄(s) + H₂O(g)

When 1 mole of Fe₂O₃(s) reacts, 2.00 kJ of energy are evolved. Energy is an extensive property. In the balanced equation there are 3 moles of Fe₂O₃(s), so the evolved energy is:

[tex]3molFe_{2}O_{3}.\frac{2.00kJ}{1molFe_{2}O_{3}} =6.00kJ[/tex]

By convention, when energy is evolved it takes the negative sign. At constant pressure, the thermochemical equation is:

3 Fe₂O₃(s) + H₂(g) ⇒ 2 Fe₃O₄(s) + H₂O(g)    ΔH° = -6.00 kJ

where

ΔH° is the standard enthalpy of reaction (heat released at constant pressure)

Imatinib is a small molecule kinase inhibitor. The BCR-ABL kinase can phosphorylate a series of downstream substrates, leading to proliferation of mature granulocytes. Bcr-Abl kinase substrate is the tyrosine. The Protein Tyrosine Kinase activity is an important requirement for malignant transformation, and that it cannot be complemented by any downstream effector, though not all interactions of BCR-ABL with other proteins are phosphotyrosine dependent.

Answer:

1) 4.35 atm

2) 36.88 °C

Explanation:

1) Because the temperature and number of moles remained constant, we can use the formula P₁V₁=P₂V₂

3.00 L * 1.45 atm = P₂ * 1.00 L

P₂ = 4.35 atm

2) First we use a geometrical formula to calculate the volume of the spherical balloon when it has a diameter of 50.0 and of 51.0 cm.

V₁ = 4/3 * π*(50/2)³ = 65449.85cm³

V₂ = 4/3 * π*(51/2)³ = 69455.90cm³

Then we use T₁V₂=T₂V₁, keeping in mind using Kelvin as the unit for temperatures:

292.16 K *  69455.90cm³ = T₂ * 65449.85cm³

T₂ = 310.04 K = 36.88 °C

The final pressure of the chlorine gas in the cylinder is 4.35 atm as per Boyle's Law. The temp on a hot summer day outside can be found using Charles's Law after a series of steps starting with converting the diameter to radius then to volume, adjusting for Kelvin, and then solving for T2 with Charles's Law.

The subjects of these problems pertain to gas laws, specifically, Boyle's Law and Charles's Law.

1) According to Boyle's Law, the pressure and volume of a gas have an inverse relationship when the temperature and the number of moles remain constant. Thus, if the volume is decreased, the pressure should increase. We can calculate the final pressure with the formula P1*V1 = P2*V2. Substituting the given figures: 1.45 atm * 3.00 L = P2 * 1.00 L. Solving for P2, the final pressure of the gas is 4.35 atm.

2) With Charles's Law, the volume and temperature of a gas have a direct relationship when pressure and the number of moles remain constant. Converting the diameters to radii (25.0 cm to 26.0 cm) and using the volume formula of a sphere, you find the volume before and after. The formula for Charles's Law is V1/T1 = V2/T2. However, all temperatures need to be in Kelvin, so 19.0 C converts to 292.15 K. Substituting the calculated volumes and temperatures, solve for T2. This will give you the temperature outside in Kelvin. Convert to Celsius for a meaningful interpretation.

https://brainly.com/question/12669509

#SPJ3

Answer:

The final volume of the cylinder is 1.67 L

Explanation:

Step 1: Data given

Initial volume = 0.250 L

external pressure = 2.00 atm

Expansion does 288 J of work on the surroundings

Step 2: Definition of reversible work:

Wrev = -P(V2-V1) = -288 J

The gas did work, so V2>V1  (volume expands) and the work has a negative sign.(Wrev<0)

V2 = (-Wrev/P)  + V1

⇒ with Wrev = reverse work (in J)

⇒ with P = the external pressure (in atm)

⇒ with V1 = the initial volume

We can see that your pressure is in  atm  and energy in J

To convert from J to L * atm we should use a convenient conversion unit using the universal gas constants :

R = 8.314472 J/mol *K and R= 0.08206 L*atm/K*mol

V2 =- (-288 J * (0.08206 L*atm/K*mol  /8.314 J/mol *K))/2.00 atm  + 0.250L

V2 = 1.67 L

The final volume of the cylinder is 1.67 L

The final volume of the cylinder after the expansion is 1.673 liters. This was found by calculating the change in volume using the work done on the surroundings and the external pressure, and adding it to the initial volume.

To calculate the final volume of the cylinder after expansion, we need to use the work done on the surroundings and the external pressure. Work (W) is related to pressure (P) and volume change (ΔV) by the equation W = -PΔV, where the pressure is constant and work done on the surroundings is negative.

In this case, we know that the work done on the surroundings is 288 J and the external pressure is 2.00 atm. Since 1 L·atm is equivalent to 101.3 J, we convert the external pressure to joules by multiplying by the volume change ΔV in liters:

288 J = -(2.00 atm) · ΔV · 101.3 J/L·atm

Therefore, to find ΔV we divide 288 J by the product of 2.00 atm and 101.3 J/L·atm:

ΔV = -288 J / (2.00 atm · 101.3 J/L·atm)

ΔV = -1.423 L (taking the absolute value, since volume change is positive upon expansion)

The initial volume was 0.250 L, thus the final volume is:

V_final = V_initial + ΔV

V_final = 0.250 L + 1.423 L

V_final = 1.673 L

Sulfur and Fluorine are nonmetals so they will form covalent bonds to gain stability. To do so, they will follow the octet rule: they will share enough electrons so as to have their valence shell complete with 8 electrons.

Sulfur is in the Group 16 in the Periodic Table and has 6 valence electrons. Thus it must share 2 pairs of electrons to reach the octet.

Fluorine is in the Group 17 in the Periodic Table so each F has 7 valence electrons. Thus, each F needs to share 1 pair of electrons to reach the octet.

As a consequence, they will be bonded in the order F - S - F, with a single bond between each pair of atoms.

Answer:

11.3 L

Explanation:

Initially, the cylinder had n₁ = 0.120 mol of gas in an initial volume V₁ = 2.18 L. At the end, it had n₂ = 0.621 mol in an unknown volume V₂. According to the Avogadro's law, in the same conditions of pressure and temperature, the volume is directly proportional to the number of moles.

[tex]\frac{V_{1}}{n_{1}} =\frac{V_{2}}{n_{2}} \\V_{2}=\frac{V_{1}\times n_{2} }{n_{1}} =\frac{2.18L \times 0.621mol}{0.120mol} =11.3L[/tex]

Answer:

The concentration of the HNO3 solution is 0.103 M

Explanation:

Step 1: Data given

Volume of the unknow HNO3 sample = 0.125 L

Volume of 0.200 M Ba(OH)2 = 32.3 mL = 0.0323 L

Step 2: The balanced equation

2HNO3(aq) + Ba(OH)2 ( aq ) ⟶ 2H2O ( l ) + Ba( NO3)2 (aq)

Step 3:

n2*C1*V1 = n1*C2*V2

⇒ n2 = the number of moles of Ba(OH)2 = 1

⇒ C1 = the concentration of HNO3 = TO BE DETERMINED

⇒ V1 = the volume of the HNO3 solution = 0.125 L

⇒ n1 = the number of moles of HNO3 = 2

⇒ C2 = the concentration of Ba(OH)2 = 0.200 M

⇒ V2 = the volume of Ba(OH)2 = 0.0323 L

1*C1 * 0.125 L = 2*0.200M * 0.0323 L

C1 = (2*0.200*0.0323)/0.125

C1 = 0.103 M

The concentration of the HNO3 solution is 0.103 M

Answer:

The correct answer is option E.

Explanation:

The Gibbs free energy is given by expression:

ΔG = ΔH - TΔS

ΔH = Enthalpy change of the reaction

T = Temperature of the reaction

ΔS = Entropy change

We have :

ΔH = -720.5 kJ/mol =  -720500 J/mol (1 kJ = 1000 J)

ΔS = -263.7 J/K

T = 141.0°C = 414.15 K

[tex]\Delta G = -720500 J/mol - (414.15 K\times (-263.7 J/K))[/tex]

[tex]= -611,288.64 J/mol = -611.28 kJ/mol\approx -611.3 kJ/mol[/tex]

The Gibb's free energy of the given reaction at 141.0°C is -611.3 kJ/mol.

Using the temperature in Kelvin and the given values, ΔG is calculated to be -611.3 kJ/mol, corresponding to option E.

To determine the Gibbs free energy (ΔG) at 141.0 degrees Celsius for the reaction involving the formation of phosphorous trichloride (PCl3) from its elements, we can use the following formula:

ΔG = ΔH - TΔS

Given data at 25.0 degrees Celsius (298.15 K):

ΔH = -720.5 kJ/mol

ΔG = -642.9 kJ/mol

ΔS = -263.7 J/K = -0.2637 kJ/K

Convert temperature from Celsius to Kelvin for 141.0 degrees Celsius: T = 141.0 + 273.15 = 414.15 K

Now calculate ΔG at 414.15 K:

ΔG = ΔH - TΔS = -720.5 kJ/mol - (414.15 K * -0.2637 kJ/K) = -720.5 kJ/mol + 109.19 kJ/mol = -611.31 kJ/mol

The closest answer choice is -611.3 kJ/mol which aligns with option E.

Answer:

The standard reduction potential E°cell (Cr6+/Cr3+) is -0.13V

Explanation:

Step 1: Data given

3 Ni^2+(aq) + 2 Cr(OH)3(s) + 10 OH− (aq) → 3 Ni(s) + 2 CrO4^2−(aq) + 8 H2O(l) ΔG∘ = +87000 J/mol

Ni2+(aq) + 2 e− → Ni(s)    E∘red = -0.28 V

Step 2: The half reactions:

Cathode:  Ni2+(aq) + 2 e− → Ni(s)    E° = -0.28 V

Anode: CrO4^2-(aq) + 4H2O(l) +3e- → Cr(OH)3(s) + 5OH- (aq)   E°= unknown

Step 3: Calculate E°cell

ΔG° = -n*F*E°cell

⇒ with ΔG° = the gibbs free energy

⇒ n = the number of electrons in the net reaction = 6

⇒ F = the Faraday constant = 96485 C

⇒ E°cell= the standard cell potential

Step 4: Calculate E°(Cr6+/Cr3+

E°cell= ΔG°/(-n*F)

E°cell = 87000 /(-6*96485)

E°cell = -0.150 V

E°cell = E°(Ni2+/Ni) - E°(Cr6+/Cr3+)

E°(Cr6+/Cr3+) = -0.13V

The standard reduction potential E°cell (Cr6+/Cr3+) is -0.13V

Answer:

b. reactant molecules collide more frequently and with greater energy per collision

Explanation:

As the temperature of a reaction is increased, the rate of the reaction increases because the reactant molecules collide more frequently and with greater energy per collision. When temperature is increased there is an increase in the kinetic energy of the molecules. The more the molecules move the more they collide. According to the collision theory there should be enough energy to allow bonds to be formed during a chemical reaction hence the need for greater energy per collision. Also the rate of reaction is directly proportional to the number of collisions that occur.