The Rate And Extent Of Chemical Change- Topic 6

Question 1

Collision theory

Answer 1

More frequent collisions-> faster rate of reaction
More kinetic energy-> more energy transferred during collisions-> particals collide with enough energy for collisions to be successful

Question 2

Activation energy

Answer 2

The minimum amount of energy that particles need to react.
Particles need this much energy to break the bonds in the reactants and start the reaction

Question 3

The rate of reaction depends on four things…

Answer 3

-Temperature
-Concentration
-Surface area
-Catalyst

Question 4

Increasing temperature on rate of reaction

Answer 4

1. When increasing the temperature, the particles all move faster
2. This means that they will collide more frequently
3. The faster they move, the more energy they have, so more of the collisions will have enough energy to make the reaction start

Question 5

Increasing concentration on the rate of reaction

Answer 5

1. More concentrated, means more particles colliding in the same volume of solvent
2. This makes collisions mire frequent

Question 6

Increasing the pressure on rate of reaction

Answer 6

1. When increasing pressure of a gas, means same number of partials occupies a smaller space
2. Makes collisions between the reactant particles more frequent

Question 7

Increasing surface area on the rate of reaction

Answer 7

More frequent collisions

Question 8

What is a catalysts?

Answer 8

A catalysts is a substance that speeds up the rate of reaction without being used up in the reaction itself. This means that it is not part of the overall reaction equation.

Question 9

Using a catalysts for rate of reaction

Answer 9

They speed up the rate of reaction as they lower the activation energy needed to start the reaction

Question 10

How do catalysts work?

Answer 10

They work by decreasing the activation energy needed for the reaction to occur. They do this by providing an alternate reaction pathway with a lower activation energy.

Question 11

Biological catalysts

Answer 11

Enzymes- they catalyse reactions in living things