Reversible and Equilibrium

Which of the following is a characteristic of reversible reactions?

• They can only proceed in one direction.

• They can proceed to completion.

• They can reach equilibrium.

• None of the above

Which of the following is an example of an irreversible reaction?

• The combustion of methane

• The decomposition of calcium carbonate in a closed system

• The formation of a metal oxide from a metal and oxygen

• The breakdown of water into hydrogen and oxygen using electricity

Which of the following equations represents an irreversible reaction?

• 2SO2(g) + O2(g) ⇌ 2SO3(g)

• C8H18(l) + 12 1/2 O2(g) → 8CO2(g) + 9H2O(l)

• H2(g) + I2(g) ⇌ 2HI(g)

• N2O4(g) ⇌ 2NO2(g)

Which of the following is not a measure of the extent of a reaction?

• The change in concentration of reactants over time

• The change in concentration of products over time

• The change in mass of the reactants over time

• The total number of reactant molecules

Which of the following statements is true regarding the relationship between rate and extent of a reaction?

• The rate and extent of a reaction are independent of each other.

• A slow reaction will always have a low extent.

• A fast reaction will always have a high extent.

• A fast reaction will always have a low extent.

Which of the following statements best describes the extent of a chemical reaction?

• It is the amount of product obtained in a reaction.

• It is the amount of reactant obtained in a reaction.

• It is the proportion of products that have formed reactants.

• It is the proportion of reactants that have formed products.

If a chemical reaction has a theoretical yield of 50 grams and an actual yield of 40 grams, what is the percentage yield?

• 40%

• 50%

• 80%

• 125%

The equilibrium constant, K, is a measure of what aspect of a chemical reaction?

• The rate of the reaction

• The yield of the reaction

• The extent of the reaction

• The activation energy of the reaction

In a dynamic equilibrium system, which of the following is true?

• The forward reaction rate is faster than the reverse reaction rate.

• The reverse reaction rate is faster than the forward reaction rate.

• The forward reaction rate is equal to the reverse reaction rate.

• The forward and reverse reactions have stopped completely.

Which of the following is not true for a system in dynamic equilibrium?

• Reactants are constantly being formed.

• The temperature steadily increases over time.

• The total gas pressure of the system is constant.

• The rate of the forward reaction is equal to the rate of the backward reaction.