Rate Of Reactions

Question 1

Particle theory

Answer 1

Particle theory
→ all matter is made up of atoms and these atoms are constantly moving.
→ they all have kinetic energy.
→ the faster the particles move the more kinetic energy they have.

Question 2

Collision theory

Answer 2

Collision theory
→ for any chemical reaction to occur particles must collide. To do this they need to move so they must have kinetic energy.
→ the particles must collide with enough energy and at the correct orientation.
→ example: to make a loud sound when we clap our hands, our hands must collide with enough energy and at the correct orientation.

Question 3

Temperature

Answer 3

→ heat energy gives particles more kinetic (movement) energy.

→ they move faster and collide more often (more collisions per second).

→ more particles have the minimum energy needed to react (activation energy).

→ so there are more successful collisions per second and the reaction rate is higher.

Question 4

Concentration

Answer 4

Concentration

→ a higher concentration has more particles in a given volume (e.g. more particles per mL).

→ there will be more collisions per second between particles.

→ so there are more successful collisions per second and the reaction rate is higher.

Question 5

Surface area

Answer 5

Surface Area

→ increasing the surface area (chopping reactants into smaller pieces) exposes more particles available to collide.

→ there will be more collisions per second between particles.

→ so there are more successful collisions per second and the reaction rate is higher.

Question 6

Catalyst

Answer 6

Use of a catalyst

→ a catalyst provides a different reaction path with a lower activation energy.

→ more particles now have the minimum energy needed to react.

→ so there will be more collisions per second between particles with more successful collisions per second and the reaction rate is higher.