Rate of Reaction End of Unit Test

Question 1

Define Rate of Reaction.

Answer 1

The rate of reaction is how much Reactant is used up or how much Product is formed in a given time.

Question 2

How can we measure Rate of Reaction?

Answer 2

Vol of Gas Produced
Mass increase (If gas is a reactant) 
Mass decrease (If gas is a product)

Question 3

What are the equations for Rate of Reaction?

Answer 3

Mass Change / Time (g/s)

Vol. Change / Time (cm^3/s)

Question 4

LOOK AT GRAPHS

Answer 4

.

Question 5

How can someone increase the surface area of an object?

Answer 5

Cutting substance into smaller pieces, squashing the substance, poking holes in the substance

Question 6

State the Variables and their definitions -

Answer 6

Dependent Variable - The variable you are MEASURING
Independent Variable - Variable you are CHANGING
Control - Variables to be kept the same throughout the experiment

Question 7

Revise required Practicals for effect of Concentration, Surface Area and Temperature

Answer 7

.

Question 8

What is important to remember when plotting the rate of reaction?

Answer 8

The amount of reactant left against time and the amount of product formed against time will be common in exams

Question 9

What is the Collision Theory?

Answer 9

Collision theory states that the rate of reaction depends on 2 things -

Frequency of collisions of reacting particles
and
Energy transferred during a collusion

Question 10

How can we explain the effect of concentration on the rate of reaction in terms of collision theory?

Answer 10

The more concentrated the particles are, the more SUCCESSFUL collisions there are because the particles are closer together, therefore the rate of reaction is higher.

Question 11

How can we explain the effect of surface area on the rate of reaction in terms of collision theory?

Answer 11

The higher the surface area, the higher the rate of reaction because a higher surface area means more particles will hit the surface therefore more successful collisions, thus a higher rate of reaction.

Question 12

How can we explain the effect of temperature on the rate of reaction in terms of collision theory?

Answer 12

When temperature increases, the particles move faster, and particles that move faster collide more, and they also have more energy within the particles, so therefore the rate of reaction increases as temperature increases.

Question 13

What is the minimum amount of energy required for a reaction to start?

Answer 13

Activation Energy

Question 14

What is a catalyst?

Answer 14

A substance which can speed up the rate of reaction without being changed or used up in the reaction

Question 15

How do catalysts work?

Answer 15

They work by reducing the activation energy, so particles need less energy for there to be successful collisions

Question 16

How do catalysts reduce activation energy?

Answer 16

They provide a different path to the reaction, and this path has a lower activation energy.