G10 Chemistry Final Exam Review Part 4

What is a reversible reaction?

• A reaction that goes to completion in one direction only

• A reaction that stops when the reactants are used up

• A reaction that occurs in both the forward and reverse directions

• A reaction that cannot be reversed under any condition

What does the double arrow (⇌) in a chemical equation represent?

• A spontaneous reaction

• A single-step reaction

• A reversible reaction

• An incomplete reaction

What is meant by dynamic equilibrium in a closed system?

• Reactants are completely used up

• No reactions are occurring

• Forward and reverse reactions occur at the same rate

• Products dominate the mixture

In dynamic equilibrium, what remains constant?

• The rate of the forward reaction only

• The concentration of reactants and products

• The energy of the system

• The temperature and pressure

Which condition is necessary for a chemical system to reach dynamic equilibrium?

• Open system

• Constant addition of reactants

• Closed system

• Catalyst must be present

Which of the following is true at dynamic equilibrium?

• No products are formed

• The system is static

• The forward and reverse reactions have stopped

• The forward and reverse reaction rates are equal

A reaction mixture has reached dynamic equilibrium. What will happen if more reactant is added?

• The reaction will stop

• The system will shift to produce more products

• The reverse reaction will stop

• Nothing will change

Which of the following best describes a closed system?

• A system where products escape into the air

• A system where mass and energy can freely enter and leave

• A system sealed off from its surroundings, but energy can still be exchanged

• A system where only products are removed

At dynamic equilibrium, how can you tell that reactions are still occurring?

• There is no observable change

• Gas is always released

• Color changes constantly

• Concentration increases continuously

In the equilibrium reaction: N₂(g) + 3H₂(g) ⇌ 2NH₃(g), Which of the following will increase the yield of ammonia (NH₃)?

• Increasing the temperature

• Decreasing the pressure

• Removing NH₃ as it forms

• Adding an inert gas