Chapter C8 Rates And Equilibrium

Question 1

What is the rate of a chemical reaction?

Answer 1

How fast reactants turn into products

Question 2

What are the three techniques used to work out the rate of reaction?

Answer 2

Measuring decreasing mass of a reaction mixture
Measuring the increasing volume of gas given off
Measuring the decreasing light passing through a solution

Question 3

Five main factors that affect reaction rate

Answer 3

Temperature 
Surface area of solid 
Concentration of solutions 
Pressure of gases 
Catalyst

Question 4

What is collision theory?

Answer 4

An explanation of chemical reactions in terms of reacting particles colliding with sufficient energy for a reaction to take place

Question 5

What is activation energy?

Answer 5

The minimum amount of energy particles need before they can react

Question 6

Why does raiding the temperature increase reaction time?

Answer 6

Particles collide more often

Particles collide with more energy

Question 7

What does increasing pressure of reacting gases also increase?

Answer 7

Frequency of collisions/ rate of reaction

Question 8

What is a catalyst?

Answer 8

Substance that changes the rate of reaction

Question 9

How do catalysts work?

Answer 9

Provide an alternative reaction path to the products with a lower activation energy than the reaction without the catalyst present- a higher proportion of the reactant particles have sufficient energy to react

Question 10

Advantages of using a catalyst?

Answer 10

Saves money and the environment (less fossil fuels required)

Question 11

Does a catalyst get used up in a reaction?

Answer 11

No

Question 12

What symbol is used to show reversible reactions?

Answer 12

Half arrows

Question 13

Do reversible reactions lose or gain energy?

Answer 13

No- one reaction will be either exothermic or endothermic, and the opposite will be the other

Question 14

What is a closed system?

Answer 14

A system in which no matter enters or leaves

Question 15

What is equilibrium?

Answer 15

The rate of the forward reaction equals the rate of the reverse reaction?

Question 16

What is le chateliers principle?

Answer 16

When a change in conditions is introduced to a system at equilibrium the position of equilibrium shifts as to cancel out the change

Question 17

What will increasing pressure do to gaseous reversible reactions?

Answer 17

Favour one side of the reaction in order to allow the reaction to reach equilibrium quicker

Question 18

What will increasing pressure do during equilibrium if there are two gases with the same number of molecules?

Answer 18

Nothing, but will sped up the rate of the forward and reverse reaction

Question 19

What does increasing temperature do to an exothermic reaction?

Answer 19

Favours the endothermic reaction

Question 20

What does increasing temperature do to an endothermic reaction?

Answer 20

Favours the exothermic reaction

Question 21

On a rate of reaction graph, what does a steeper stope mean?

Answer 21

A faster reaction