C8 - Rates and Equilibrium

Question 1

How do you calculate the rate of a reaction?

Answer 1

Rate of Reaction = Quantity of Reactant Used / Time

Rate of Reaction = Quantity of Product Formed / Time

Question 2

What is collision theory?

Answer 2

The idea that particles need to collide with enough energy - the activation energy - to react.

Question 3

How can the rate of reaction be increased?

Answer 3

• Increasing surface area of reactants so that more material is exposed at any given time.
• Increasing temperature so particles have more energy and bounce around (and into each other) more.
• Increase concentration or pressure so there is less free space and travel time between each particle.
• Introduce catalysts so that the frequency of collisions that result in reaction increases.

Question 4

What is a reversible reaction?

Answer 4

A reaction where the products can react together again to make the original reactants.

One reaction is always exothermic, and one is always endothermic.

It will transfer the same amount of energy to the surroundings to reverse the reaction as it did to perform the reaction in the first place.

Question 5

What is a dynamic equilibrium?

Answer 5

A dynamic equilibrium is where products constantly bounce back and forth between each side of the reaction in a closed environment, resulting in a consistent ratio of product set A to set B.

Question 6

How can you effect the dynamic equilibrium in a reaction?

Answer 6

• Increasing pressure of a gas will favour the reaction that produces the fewest molecules of gas, and vice versa.
• Increasing temperature favours the endothermic reaction. Decreasing temperature favours the exothermic reaction.