Honors Chemistry

Name: ______Date: ______Mods: ______

Unit 14 Review Packet (Kinetics & Equilibrium)

1)Determine if the reaction rate increases or decreases (a or b) with each of the following changes:

  1. Causes reaction rate to speed up b. Causes reaction rate to slow down

______Grind up solid reactants

______Increase reactant concentrations

______Add a catalyst

______Decrease temperature of reaction

______Increase activation energy

______Decrease reactant concentrations

______Increase temperature of reaction

______Dissolve solid reactants to form aqueous solutions

______Decrease activation energy

2)Based on your knowledge of zero order, first order, and second order reactants, answer the following questions:

  1. For the reaction A + B  C, two trials of the reaction were completed where the concentration of reactant B was kept constant. Increasing the concentration of reactant A from 1.0 M to 2.0 M causes the rate of the reaction to increase by a factor of 4. Reactant A is therefore a ______order reactant.
  1. For A + B  C + D, two trials of the reaction were completed where the concentration of reactant A was kept constant. The concentration of reactant B was decreased by one-half between trial 1 and trial 2, and the reaction rate was reduced to one-half the original rate. Reactant B is therefore a ______order reactant.

3)For the reaction 2 A + 3 B  3 C + 2 D, if the concentration of A is doubled, the reaction rate doubles. If the concentration of B is quadrupled, there is no change in the rate of the reaction. Determine the order of reaction with respect to each reactant and the overall order of reaction. Write the rate law for the reaction.

  1. Order of reactant A: ______b. Order of reactant B: ______
  1. Rate Law:

4)Use the following reaction as an example of how a rate law can be determined from experimental data:

CH3CHO (g) CH4 (g) + CO (g)

Experimental Data from the Decomposition of CH3CHO
Initial Concentration [CH3CHO] / Initial Concentration [CO] / Initial Rate (M/s)
Trial 1 / 0.30 / 0.20 / 0.60
Trial 2 / 0.10 / 0.30 / 0.067
Trial 3 / 0.10 / 0.20 / 0.067
  1. Determining the order with respect to CH3CHO:

From this evaluation, the order of CH3CHOis ______.

  1. Determining the order with respect toCO:

From this evaluation, the order of CO is ______.

  1. What is the rate law expression for this reaction?

5)Balance the equations below and write the equilibrium expressions for each reaction:

  1. ___ Pb(OH)2 (aq) + ___ HCl (aq) a.

___ H2O (l) + ___ PbCl2 (s)

  1. ___ RbNO3 (aq) + ___ BeF2 (aq) b.

 ___ Be(NO3)2 (aq) + ___ RbF (aq)

  1. ___ NaF (aq) + ___ Br2 (l) c.

 ___ NaBr (aq) + ___ F2 (g)

  1. ___ NaClO3 (aq) ___ NaCl (aq) + ___ O2 (g) d.

6)Using Le Chatelier’s Principle, place a check mark next to all of the possible stresses which would cause the equilibrium reaction below to shift is a way which DECREASE the concentration of F2?

N2 (g) + 3 F2 (g) 2 NF3 (g) ∆H = – 127 kJ

______increase the volume of the reaction container

______decrease the volume of the reaction container

______increase the temperature ______decrease the temperature

______increase[N2] ______decrease [N2]

______increase[NF3] ______decrease [NF3]

7)For an equilibrium expression (at a given temperature), the equilibrium constant (Keq) can be determined.

  1. If Keq> 1, the ______(products of reactants) predominate/are favored
  1. If Keq 1, the ______(products of reactants) predominate/are favored

8)Use the Keq’s given to determine which reaction (1 or 2) the statements below best describe:

Rxn #1: COCl2 (g) + heat CO (g) + Cl2 (g) Keq = 2.2 x 10–10

Rxn #2: 2 NO2 (g) N2O4 (g) + heat Keq = 215

  1. ______At equilibrium, the forward reaction is favored
  1. ______At equilibrium, the reverse reaction is favored
  1. ______Decreasing temperature favors the forward reaction
  1. ______Increasing the volume favors the forward reaction
  1. ______Decreasing the volume favors the forward reaction
  1. ______At equilibrium, there is a higher concentration of reactants than products
  1. ______At equilibrium, there is a higher concentration of products than reactants

9)Given the equilibrium expression of CO(g) + 2 H2(g)CH3OH(g), if the equilibrium concentrations are [CO] = 0.0911 M, [H2] = 0.0822 M, [CH3OH] = 0.00892 M, what is the value of the equilibrium constant? Does the equilibrium favor reactants or products?

10)Once a system hasreached equilibrium, are the following true (T) or false (F)?

  1. _____ The reaction is finished, no more products are forming.
  1. _____ The concentrations of the reactants and the products are equal.
  1. _____ The concentrations are no longer changing.
  1. _____ The reaction is not over, but will continue forever if isolated.
  1. _____ The speed at which products form equals the speed at which reactants form.

11)For the reaction below, if the Keq at 145ᵒC is 0.0533, If [SiH4] = 0.34atm; [O2] = 0.22atm; [SiO2] = 0.35 atm; and [H2O] = 0.20 atm, what would be the reaction quotient (Q) of this reaction? In which direction would this reaction need to proceed in order to achieve equilibrium?

SiH4 (g) + 2 O2 (g)SiO2 (g) + 2 H2O (g)

12)Use Le Chatelier’s Principle to determine which direction (left or right) the reaction below will shift in order to restore equilibrium when each of the following stresses are applied.

O2 (g) +2H2 (g) 2H2O (g) ΔH= –125.7 kJ

a.The temperature is increased ______

b.The concentration of H2 decreases ______

c.The concentration of H2O increases ______

d.The volume of the container decreases ______

e.The concentration of O2 increases ______

13)Initially, 1.50 atm N2(g) and 3.50 atm H2(g) were combinein a container at 700 °C. As a result of the reaction, the equilibrium concentration of NH3(g) was 0.540 atm. What is the value of the equilibrium constant for this reaction at the given temperature of 700 °C.

Balanced: N2(g) + 3H2(g)+ 2 NH3(g)

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14)Given the reaction below, if initial pressures of H2 (g) and I2 (g) were both 0.10 atm and the Keq (at 600 Kelvin) is 0.016,what will be the pressures of the reactants and product at equilibrium?

Balanced: H2(g)+ I2(g)2 HI(g)

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