Chemical Equilibrium Basics

What is the main difference between heterogeneous and homogeneous equilibrium?

• Heterogeneous equilibrium involves only reactants; homogeneous equilibrium involves only products.

• Heterogeneous equilibrium occurs in closed systems; homogeneous equilibrium occurs in open systems.

• In heterogeneous equilibrium, reactants and products are in different phases; in homogeneous equilibrium, all reactants and products are in the same phase.

• In heterogeneous equilibrium, reactants and products are in the same phase; in homogeneous equilibrium, all reactants and products are in different phases.

Give an example of a heterogeneous equilibrium reaction.

• The reaction: CaCO3(s) + CO2(g) ⇌ CaO(s) + CO2(g)

• The reaction: H2(g) + I2(g) ⇌ 2HI(g)

• The reaction: N2(g) + 3H2(g) ⇌ 2NH3(g)

• The reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g)

Explain why the equilibrium constant for a heterogeneous reaction may include only the concentrations of gases or liquids.

• The concentrations of solids are highly variable and affect the equilibrium position significantly.

• The concentrations of solids are constant and do not affect the equilibrium position.

• The concentrations of gases are not involved in the reaction.

• The equilibrium constant is not affected by the nature of the substances involved.

How does the presence of a catalyst affect the position of equilibrium in a homogeneous reaction?

• A catalyst shifts the equilibrium to the left in a homogeneous reaction.

• A catalyst increases the concentration of reactants at equilibrium in a homogeneous reaction.

• A catalyst does not affect the position of equilibrium in a homogeneous reaction.

• A catalyst decreases the rate of the reaction in a homogeneous reaction.

Discuss the role of temperature in shifting the equilibrium in a heterogeneous system.

• Increasing temperature always shifts the equilibrium towards the reactants

• Temperature has no impact on equilibrium in a heterogeneous system

• Temperature affects the equilibrium by changing the rate of reactions and shifting it towards the endothermic or exothermic direction.

• Temperature only affects homogeneous systems, not heterogeneous ones

What is the effect of pressure changes on a heterogeneous equilibrium?

• Pressure changes increase the rate of reaction in a heterogeneous equilibrium.

• Pressure changes shift the equilibrium towards the side with fewer moles of gas.

• Pressure changes cause the equilibrium to completely shift to one side.

• Pressure changes do not affect a heterogeneous equilibrium.

Describe how Le Chatelier's Principle applies to a homogeneous equilibrium.

• Le Chatelier's Principle does not affect homogeneous equilibrium

• In a homogeneous equilibrium, Le Chatelier's Principle always leads to a decrease in reactants

• In a homogeneous equilibrium, Le Chatelier's Principle applies by shifting the equilibrium position in response to changes in concentration, pressure, or temperature.

• Homogeneous equilibrium is not influenced by concentration, pressure, or temperature changes

Why is it important to consider the phase of reactants and products in a heterogeneous equilibrium?

• Considering the phase of reactants and products is important in a heterogeneous equilibrium because it affects the equilibrium constant expression.

• Phase changes do not influence the position of equilibrium

• The phase of reactants and products has no impact on equilibrium

• Equilibrium constants are not affected by the phase of substances

Compare and contrast the characteristics of a homogeneous and heterogeneous equilibrium.

• Homogeneous equilibrium occurs at high temperatures, while heterogeneous equilibrium occurs at low temperatures.

• Homogeneous equilibrium involves only reactants, while heterogeneous equilibrium involves only products.

• Homogeneous equilibrium is reversible, while heterogeneous equilibrium is irreversible.

• Homogeneous equilibrium involves all reactants and products in the same phase, while heterogeneous equilibrium involves reactants and products in different phases.

Explain the concept of dynamic equilibrium in a chemical reaction.

• Dynamic equilibrium is achieved when the rate of the forward reaction equals the rate of the reverse reaction, maintaining constant concentrations of reactants and products.

• Dynamic equilibrium occurs when the reaction stops completely.

• Dynamic equilibrium is only achieved in irreversible reactions.

• Dynamic equilibrium means the reaction proceeds in only one direction.