Chemical Equilibrium Concepts

The video tutorial explains the concepts of reversible and irreversible reactions, dynamic equilibrium, and closed systems. It begins by outlining the learning objectives, followed by a detailed explanation of irreversible reactions using the combustion of methane as an example. The tutorial then contrasts this with reversible reactions, using the Harbor process to illustrate how products can revert to reactants. The concept of dynamic equilibrium is introduced, explaining how forward and reverse reactions occur at the same rate, leading to constant concentrations of reactants and products. The video concludes by discussing how equilibrium can be approached from either side of a reaction.

What is a closed system in the context of chemical reactions?

• A system where energy can enter or leave but matter cannot.

• A system where matter can enter or leave but energy cannot.

• A system where both energy and matter can enter or leave.

• A system where neither energy nor matter can enter or leave.

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

• The melting of ice into water.

• The dissolution of salt in water.

• Combustion of methane and oxygen.

• The Haber process for ammonia production.

How is a reversible reaction represented in a chemical equation?

• With a single-headed arrow.

• With a double-headed arrow.

• With a dashed line.

• With a circular arrow.

What happens to the rate of the forward reaction as the concentration of reactants decreases?

• It decreases.

• It becomes zero.

• It remains constant.

• It increases.

At dynamic equilibrium, what can be said about the concentrations of reactants and products?

• They are equal.

• They are constantly changing.

• They remain constant.

• They are zero.

What is meant by dynamic equilibrium in a chemical reaction?

• The concentrations of reactants and products are equal.

• The forward and reverse reactions occur at the same rate.

• The forward and reverse reactions occur at different rates.

• The reaction has stopped completely.

In a reaction at equilibrium, is it possible for the concentration of reactants to be greater than that of products?

• Yes, it is possible.

• No, it is not possible.

• Only if the reaction is irreversible.

• Only if the reaction is exothermic.

What happens to the rate of the reverse reaction as the concentration of products increases?

• It increases.

• It remains constant.

• It becomes zero.

• It decreases.

How can equilibrium be approached from the product side?

• By starting with only reactants.

• By starting with only products.

• By changing the temperature.

• By starting with equal amounts of reactants and products.

What remains unchanged at equilibrium despite ongoing reactions?

• The temperature.

• The concentrations of reactants and products.

• The volume of the system.

• The pressure.