Rate of Reaction

Question 1

What does rate of reaction depend on?

Answer 1

1. Temperature
2. Concentration
3. Catalyst
4. Surface Area

Question 2

What is the rate of reaction formula?

Answer 2

Amount of reactant used or product formed

Time

Question 3

What are the three ways to measure rate of reaction?

Answer 3

1. Precipitation
2. Change in mass
3. Volume of gas given off

Question 4

What are the problems with precipitation?

Answer 4

1. Only works for initially transparent solutions

2. Subjective

Question 5

What are the advantages of measuring change in mass?

Answer 5

1. Rate of reaction graphs are easy to plot

2. Most accurate

Question 6

What is the problem with measuring change in mass?

Answer 6

The gas is released straight into the room.

Question 7

What instrument measures the volume of gas given off?

Answer 7

Gas syringe.

Question 8

What is the problem with measuring gas given off?

Answer 8

Vigorous reactions will blow the plunger out of the syringe.

Question 9

What catalyst is used in the decomposition of hydrogen peroxide?

Answer 9

Manganese (IV) oxide catalyst.

Question 10

Why are gas syringes accurate?

Answer 10

They usually show volumes to the nearest millilitre.

Question 11

Why does a higher temperature increase rate of reaction?

Answer 11

The particles move quicker and collide more often.

Question 12

Why does a higher concentration increase rate of reaction?

Answer 12

There are more particles so collisions are more likely.

Question 13

Why does a larger surface area increase rate of reaction?

Answer 13

There will be more area for particles to work on, so collisions are more frequent.

Question 14

What does increasing the temperature do?

Answer 14

Increasing the temperature causes faster collisions.

Question 15

What is the activation energy?

Answer 15

The minimum amount of energy needed by particles to react.

Question 16

What are the conditions needed for reactions to happen?

Answer 16

1. Collisions

2. With enough energy

Question 17

What is a catalyst?

Answer 17

A catalyst is a substance which speeds up a reaction, without being changed or used up in the reaction.

Question 18

What are the advantages of catalysts?

Answer 18

1. Saves money (less operating time)

2. Sustainable development (lower temperature)

Question 19

What are the disadvantages of catalysts?

Answer 19

1. Expensive
2. Each catalyst only works for one reaction
3. Catalysts can be poisoned by impurities

Question 20

What is an exothermic reaction?

Answer 20

An exothermic reaction is one which gives out energy to the surroundings usually in the form of heat and usually shown by a rise in temperature.

Question 21

What are three types of exothermic reactions?

Answer 21

1. Combustion
2. Neutralisation
3. Oxidation

Question 22

What are everyday uses for exothermic reactions?

Answer 22

1. Hand warmers

2. Self heating hot chocolate

Question 23

What is an endothermic reaction?

Answer 23

An endothermic reaction is one which takes in energy from the surroundings, usually in the form of heat, and is usually shown by a fall in temperature.

Question 24

What is an example of an endothermic reaction?

Answer 24

Thermal decomposition.

Question 25

What is a reversible reaction?

Answer 25

Exothermic one way and endothermic the other.