LeChatelier's Review

Ammonia (NH3) is produced commercially by the Haber reaction: N2 (g) + 3 H2 (g) ↔ 2 NH3 (g) + heat

The formation of ammonia is favored by

• an increase in pressure

• a decrease in pressure

• removal of N2 (g)

• removal of H2 (g)

Given the reaction at equilibrium: 2 SO2(g) + O2(g) ↔ 2 SO3(g) + heat. Which change will shift the equilibrium to the right?

• increasing the temperature

• decreasing the pressure

• increasing the amount of SO2(g)

• decreasing the amount of O2(g)

Which system at equilibrium will be least affected by a change in pressure?

• 3 H2(g) + N2(g) ↔ 2 NH3(g)

• 2 S(s) + 3 O2(g) ↔ 2 SO3(g)

• AgCl(s) ↔ Ag+(aq) + Cl– (aq)

• 2 HgO(s) ↔ 2 Hg(g) + O2(g)

Given the equilibrium reaction: 2 SO2 (g) + O2 (g) ↔ 2 SO3 (g) + Heat. When the pressure on the system is increased, the concentration of SO3 will

• decrease

• increase

• remain the same

Given the reaction: N2(g) + O2(g) + 182.6 kJ ↔ 2 NO(g)

Which change would cause an immediate increase in the rate of the forward reaction (i.e., cause shift to the right)?

• increasing the concentration of NO(g)

• increasing the concentration of N2(g)

• decreasing the reaction temperature

• decreasing the reaction pressure

Given the Haber reaction at equilibrium: N2(g) + 3 H2(g) ↔ 2 NH3(g) + heat

Which stress on the system will decrease the production of NH3(g)?

• increasing the concentration of N2(g)

• increasing the pressure on the system

• decreasing the concentration of H2(g)

• decreasing the temperature on the system

2SO2(g) + O2(g) 2SO3(g)

Which of the following stresses will shift the equilibrium to the left?

• O2 is added to the reaction.

• SO3 is removed from the reaction.

• SO3 is added to the reaction.

• The volume is decreased.

• Ar(g) is added to the reaction.

True or False: NH4Cl(s) + heat NH3(g) + HCl(g)

The forward reaction above is exothermic.

• True

• False

True or False: NH4Cl(s) + heat NH3(g) + HCl(g)

The production of ammonia (NH3) from ammonium chloride (NH4Cl) will increase at higher temperature.

• True

• False

True or False: NH4Cl(s) + heat NH3(g) + HCl(g)

In the above reaction system, the value of Keq decreases as the temperature increases.

• True

• False