C8 - Rate Of Reactions

Question 1

How does a catalyst speed up a reaction?

Answer 1

By lowering the activation energy

Question 2

What does ‘the rate of a chemical reaction’ mean specifically?

Answer 2

How fast the reactants are changed into products

Question 3

What does the collision theory suggest?

Answer 3

The rate of a chemical reaction depends on:
- Collision frequency
- The energy transferred during a collision

Question 4

What does the collision frequency in the collision theory suggest?

Answer 4

The more collisions there are in a reaction, the faster the reaction

Question 5

What are 5 things that affect the rate of reaction?

Answer 5

Temperature
Concentration gradient
Preussire of a gas
Surface area
A ctalyst

Question 6

How does an increased temperature affect the rate of a reaction?

Answer 6

Increased temp –> particles move faster –> particles collide more frequently and a higher chance of reaction

However enzymes can denature

Question 7

How does an increased concentration of a solution affect the rate of a reaction?

Answer 7

Collisions between particles are more frequent as more particles occupy a small volume

Question 8

What is the simple equation to find the rate of reaction?

Answer 8

(Amount of reactant used / product formed) divided by time

Question 9

What are three physical ways you can measure the rate of reaction?

Answer 9

Precipitation and colour change
Change in mass
The volume of gas given off

Question 10

You can measure the rate of reaction physically using precipitation and colour change. How?

Answer 10

Record how long it takes for an ‘X’ mark, under a reacting solution, to become visible