Collision Theory

Question 1

what does the rate of chemical reaction depend on

Answer 1

• the collision frequency of reacting particles

- the energy transferred during a collsion

Question 2

what does the rate of collision of reacting particles mean

Answer 2

• how often they collide

- so the more successful collisions there are, the faster the reaction is

Question 3

what is activation energy

Answer 3

the minimum energy that particles need to react when they collide

Question 4

when can reactions only happen

Answer 4

• when the particles collide with enough energy

- or when the activation energy of the collision is met or exceeded

Question 5

what would happen if you were to increase the number of collisions or the energy with which the particles collide with

Answer 5

the reactions would happen more quickly

Question 6

how does temperature affect rate of reaction

Answer 6

an increase in temperature increases rate of reaction

Question 7

why does an increase in temperature result in an increase of rate of reaction in terms of kinetic energy

Answer 7

• particles are given more kinetic energy so they move faster
• faster movement results in more frequent collisions with other fast moving particles

Question 8

why does an increase in temperature result in an increase of rate of reaction in terms of collision energy

Answer 8

• higher temps increase kinetic energy
• so energy of collisions are higher as they collide at quicker speeds
• means that high temps results in more successful collisions
• as activation energy is reached and excelled more frequently

Question 9

what is meant by a solution becoming more concentrated

Answer 9

there are more particles of reactant in the same volume

Question 10

how does concentration affect rate of reaction

Answer 10

an increase in concentration increases rate of reaction

Question 11

why does an increase in concentration result in an increased rate of reaction

Answer 11

because a concentrated solution has more reactant particles in the same volume so they can collide more frequently

Question 12

what is the word used to describe the concentration of gases in a given volume

Answer 12

pressure

Question 13

how does an increase of pressure result in an increase of rate of reaction

Answer 13

• increase in pressure means that particles are more crowded
• means that the frequency of collisions will be increased
• so rate of reaction increases

Question 14

how does breaking a solid reactant into smaller pieces affect rate of reaction

Answer 14

breaking a solid reactant into smaller pieces would increase the rate of reaction

Question 15

why does breaking a solid reactant into smaller pieces result in an increased rate of reaction

Answer 15

• breaking it increases its surface area to volume ratio
• meaning more solid is exposed compared to overall volume
• particles around it will have more area to work on
• so frequency of collisions increase

Question 16

what conclusion can you draw from the change in rate of reaction from breaking a solid reactant into smaller pieces

Answer 16

the rate of reaction is faster for solids with a larger surface area to volume ratio