Question 1

Identify the intermediate in the following two-step reaction. Cr²⁺(aq)+ Sn⁴⁺(aq)⇌ Cr³⁺(aq)+ Sn³⁺(aq)Cr²⁺(aq)+ Sn³+(aq)→ Cr³+(aq)+ Sn²⁺(aq)

Accepted Answer

The intermediate in the reaction sequence is Sn^2+(aq), as it is produced in the first step and consumed in the second step.

Question 2

Which of the following statements regarding catalysts is incorrect?

Accepted Answer

In a chemical reaction, the catalyst is not shown on either the reactant or product side of the equation. This is because the catalyst is not a reactant or a product, but rather a substance that facilitates the reaction without being consumed by it.

Question 3

Which of the following changes will increase the fraction of collisions that are effective collisions?

Accepted Answer

A

Question 4

Factors that influence reaction rates include all of the following except the

Accepted Answer

The magnitude of the equilibrium constant describes the position of an equilibrium, but it does not directly affect the rate of the reaction. The other factors listed, including reaction temperature, presence of a catalyst, size of solid reactant particles, and concentration of reactants, can all influence reaction rates.

Question 5

The rate of a reaction can be increased by all of the following except

Accepted Answer

Increasing the volume of the reaction vessel will not increase the rate of the reaction. This is because increasing the volume decreases the concentration of the reactants, which will decrease the rate of the reaction according to the rate law.

Question 6

A catalyst speeds up a chemical reaction by

Accepted Answer

A catalyst provides an alternate reaction pathway with a lower activation energy, thus making it easier for the reaction to occur. This speeds up the rate of the reaction without affecting the equilibrium or changing the heat of the reaction.

Question 7

Which of the following will not increase the rate of a reaction?

Accepted Answer

All the options listed (decreasing the temperature, decreasing the concentration of the reactants, decreasing the surface area of the reactants, and removing a catalyst) are factors that would not increase the rate of a reaction. Instead, they would either slow down the reaction or have no effect on accelerating it.

Question 8

Which of the following statements regarding catalysts is incorrect?

Accepted Answer

B) is incorrect because a catalyst is not formed during the reaction; instead, it participates in the reaction by providing an alternative pathway and remains unchanged after the reaction.

Question 9

Identify any intermediates in the following three-step reaction: H₂C=CH₂ + H₃O⁺ → H₃C=CH₂⁺ + H₂O H₃C=CH₂⁺ + H₂O → CH₃CH₂OH₂⁺ CH₃CH₂OH₂⁺ + H₂O → CH₃CH₂OH + H₃O⁺

Accepted Answer

An intermediate is a species that appears in one step of a reaction mechanism but not in the overall balanced equation. In this case, it is clear that H₃O⁺, CH₃CH₂OH₂⁺, and H₂O appear in intermediate steps of the reaction but not in the overall balanced equation. Therefore, the best choice is C.

Question 10

In a chemical reaction at constant temperature, the addition of a catalyst

Accepted Answer

A catalyst provides an alternate reaction pathway with a different activation energy, effectively lowering the activation energy required for the reaction to occur. This leads to an increase in the rate of the reaction, but does not affect the equilibrium constant or the energy released in the reaction. The concentration of products at equilibrium may be affected by the catalyst, but this is dependent on the specific reaction and cannot be generalized.

Question 11

Identify any intermediates or catalysts in the following two-step reaction: Cu²⁺ + H₂ → CuH⁺ + H⁺ CuH⁺ + H⁺ + H₂C=CH₂ → Cu²⁺ + H₃C-CH₃

Accepted Answer

The answer of Identify any intermediates or catalysts in the...

Question 12

Identify the intermediate(s)in the following two-step reaction. O₃(g)⇌ O₂(g)+ O(g)O(g)+ O₃(g)→ 2O₂(g)

Accepted Answer

The answer of Identify the intermediate(s)in the following two-step reaction....

Question 13

Which of the following changes will increase the average kinetic energy of the reactants?

Accepted Answer

Increasing the temperature will increase the average kinetic energy of the reactants because temperature is directly proportional to kinetic energy according to the kinetic-molecular theory of gases. The other options (A, B, and C) do not directly affect the kinetic energy of the reactants.

Question 14

According to collision theory, the increase in the rate constant with increasing temperature is due mostly to the fact that

Accepted Answer

The fraction of collisions that have sufficient energy to react increases with increasing temperature as per collision theory. As the temperature increases, the molecules move with greater kinetic energy and collide more frequently and with more force, increasing the likelihood that they will react. This leads to an increase in the rate constant.

Question 15

Identify an intermediate in the following two-step reaction. Sn²⁺ + Fe³⁺ → Sn³⁺ + Fe²⁺ Sn³⁺ + Fe³⁺ → Sn⁴⁺ + Fe²⁺

Accepted Answer

The intermediate in the first step is Sn³⁺ and it appears again as a reactant in the second step, indicating that it is an intermediate in the overall reaction.

Question 16

Which of the images shows the molecules in a proper orientation for an effective collision for the following reaction? 2HI(g)→ H₂(g)+ I₂(g)

Accepted Answer

In order for an effective collision to occur, the molecules must collide with proper orientation and sufficient energy. In option B, the molecules are shown with the proper orientation, where the hydrogen atoms are facing each other and the iodine atoms are facing outward. This orientation allows for the formation of the products. The other images do not show the proper orientation for effective collisions.

Question 17

Identify the intermediate(s)in the following three-step reaction. Cl₂(g)⇌ 2Cl(g)CHCl₃(g)+ Cl(g)→ HCl(g)+ CCl₃(g)CCl₃(g)+ Cl(g)→ CCl₄(g)

Accepted Answer

Intermediates are species that are produced in one step and consumed in another. Cl(g) and CCl3(g) are intermediates as they are formed and then used up in subsequent steps.

Question 18

Identify any intermediates or catalysts in the following two-step reaction: H₂O₂ + 2Br⁻ + 2H⁺→ 2H₂O + Br₂ H₂O₂ + Br₂ → 2H⁺ + O₂ + 2Br⁻

Accepted Answer

Br₋ and H⁺ are regenerated in the reaction, indicating they act as catalysts. Br₂ is produced in the first step and consumed in the second, indicating it is an intermediate.

Question 19

Identify any intermediates or catalysts in the following two-step reaction: S₂O₈²⁻ + I⁻ → 2SO₄²⁻ + I⁺ I⁺ ⁺ I⁻ → I₂

Accepted Answer

I⁺ is an intermediate because it is produced in the first step and consumed in the second step of the reaction.

Question 20

The kinetics of a reaction is studied at 25ºC and at 50ºC. Which of the following statements is correct?

Accepted Answer

The correct statement is D. An increase in temperature provides molecules with more kinetic energy, increasing the number of effective collisions and leading to more successful reactions. This means a greater fraction of molecules will possess sufficient energy to react, increasing the reaction rate.

Quiz 12: Reaction Rates and Chemical Equilibrium

Identify the intermediate in the following two-step reaction. Cr²⁺(aq) + Sn⁴⁺(aq) ⇌ Cr³⁺(aq) + Sn³⁺(aq) Cr²⁺(aq) + Sn³+(aq) → Cr³+(aq) + Sn²⁺(aq)

Which of the following statements regarding catalysts is incorrect?

Which of the following changes will increase the fraction of collisions that are effective collisions?

Factors that influence reaction rates include all of the following except the

The rate of a reaction can be increased by all of the following except

A catalyst speeds up a chemical reaction by

Which of the following will not increase the rate of a reaction?

Which of the following statements regarding catalysts is incorrect?

Identify any intermediates in the following three-step reaction: H₂C=CH₂ + H₃O⁺ → H₃C=CH₂⁺ + H₂O H₃C=CH₂⁺ + H₂O → CH₃CH₂OH₂⁺ CH₃CH₂OH₂⁺ + H₂O → CH₃CH₂OH + H₃O⁺

In a chemical reaction at constant temperature, the addition of a catalyst

Identify any intermediates or catalysts in the following two-step reaction: Cu²⁺ + H₂ → CuH⁺ + H⁺ CuH⁺ + H⁺ + H₂C=CH₂ → Cu²⁺ + H₃C-CH₃

Identify the intermediate(s) in the following two-step reaction. O₃(g) ⇌ O₂(g) + O(g) O(g) + O₃(g) → 2O₂(g)

Which of the following changes will increase the average kinetic energy of the reactants?

According to collision theory, the increase in the rate constant with increasing temperature is due mostly to the fact that

Identify an intermediate in the following two-step reaction. Sn²⁺ + Fe³⁺ → Sn³⁺ + Fe²⁺ Sn³⁺ + Fe³⁺ → Sn⁴⁺ + Fe²⁺

Which of the images shows the molecules in a proper orientation for an effective collision for the following reaction? 2HI(g) → H₂(g) + I₂(g)

Identify the intermediate(s) in the following three-step reaction. Cl₂(g) ⇌ 2Cl(g) CHCl₃(g) + Cl(g) → HCl(g) + CCl₃(g) CCl₃(g) + Cl(g) → CCl₄(g)

Identify any intermediates or catalysts in the following two-step reaction: H₂O₂ + 2Br⁻ + 2H⁺→ 2H₂O + Br₂ H₂O₂ + Br₂ → 2H⁺ + O₂ + 2Br⁻

Identify any intermediates or catalysts in the following two-step reaction: S₂O₈²⁻ + I⁻ → 2SO₄²⁻ + I⁺ I⁺ ⁺ I⁻ → I₂

The kinetics of a reaction is studied at 25ºC and at 50ºC. Which of the following statements is correct?

Quiz 12: Reaction Rates and Chemical Equilibrium

Identify the intermediate in the following two-step reaction. Cr2+(aq) + Sn4+(aq) ⇌ Cr3+(aq) + Sn3+(aq) Cr2+(aq) + Sn3+(aq) → Cr3+(aq) + Sn2+(aq)

Which of the following statements regarding catalysts is incorrect?

Which of the following changes will increase the fraction of collisions that are effective collisions?

Factors that influence reaction rates include all of the following except the

The rate of a reaction can be increased by all of the following except

A catalyst speeds up a chemical reaction by

Which of the following will not increase the rate of a reaction?

Which of the following statements regarding catalysts is incorrect?

Identify any intermediates in the following three-step reaction: H2C=CH2 + H3O+ → H3C=CH2+ + H2O H3C=CH2+ + H2O → CH3CH2OH2+ CH3CH2OH2+ + H2O → CH3CH2OH + H3O+

In a chemical reaction at constant temperature, the addition of a catalyst

Identify any intermediates or catalysts in the following two-step reaction: Cu2+ + H2 → CuH+ + H+ CuH+ + H+ + H2C=CH2 → Cu2+ + H3C-CH3

Identify the intermediate(s) in the following two-step reaction. O3(g) ⇌ O2(g) + O(g) O(g) + O3(g) → 2O2(g)

Which of the following changes will increase the average kinetic energy of the reactants?

According to collision theory, the increase in the rate constant with increasing temperature is due mostly to the fact that

Identify an intermediate in the following two-step reaction. Sn2+ + Fe3+ → Sn3+ + Fe2+ Sn3+ + Fe3+ → Sn4+ + Fe2+

Which of the images shows the molecules in a proper orientation for an effective collision for the following reaction? 2HI(g) → H2(g) + I2(g)

Identify the intermediate(s) in the following three-step reaction. Cl2(g) ⇌ 2Cl(g) CHCl3(g) + Cl(g) → HCl(g) + CCl3(g) CCl3(g) + Cl(g) → CCl4(g)

Identify any intermediates or catalysts in the following two-step reaction: H2O2 + 2Br− + 2H+→ 2H2O + Br2 H2O2 + Br2 → 2H+ + O2 + 2Br−

Identify any intermediates or catalysts in the following two-step reaction: S2O82− + I− → 2SO42− + I+ I+ + I− → I2

The kinetics of a reaction is studied at 25ºC and at 50ºC. Which of the following statements is correct?

Identify the intermediate in the following two-step reaction. Cr²⁺(aq) + Sn⁴⁺(aq) ⇌ Cr³⁺(aq) + Sn³⁺(aq) Cr²⁺(aq) + Sn³+(aq) → Cr³+(aq) + Sn²⁺(aq)

Identify any intermediates in the following three-step reaction: H₂C=CH₂ + H₃O⁺ → H₃C=CH₂⁺ + H₂O H₃C=CH₂⁺ + H₂O → CH₃CH₂OH₂⁺ CH₃CH₂OH₂⁺ + H₂O → CH₃CH₂OH + H₃O⁺

Identify any intermediates or catalysts in the following two-step reaction: Cu²⁺ + H₂ → CuH⁺ + H⁺ CuH⁺ + H⁺ + H₂C=CH₂ → Cu²⁺ + H₃C-CH₃

Identify the intermediate(s) in the following two-step reaction. O₃(g) ⇌ O₂(g) + O(g) O(g) + O₃(g) → 2O₂(g)

Identify an intermediate in the following two-step reaction. Sn²⁺ + Fe³⁺ → Sn³⁺ + Fe²⁺ Sn³⁺ + Fe³⁺ → Sn⁴⁺ + Fe²⁺

Which of the images shows the molecules in a proper orientation for an effective collision for the following reaction? 2HI(g) → H₂(g) + I₂(g)

Identify the intermediate(s) in the following three-step reaction. Cl₂(g) ⇌ 2Cl(g) CHCl₃(g) + Cl(g) → HCl(g) + CCl₃(g) CCl₃(g) + Cl(g) → CCl₄(g)

Identify any intermediates or catalysts in the following two-step reaction: H₂O₂ + 2Br⁻ + 2H⁺→ 2H₂O + Br₂ H₂O₂ + Br₂ → 2H⁺ + O₂ + 2Br⁻

Identify any intermediates or catalysts in the following two-step reaction: S₂O₈²⁻ + I⁻ → 2SO₄²⁻ + I⁺ I⁺ ⁺ I⁻ → I₂