5.1 Collision theory

Question 1

describe a chemical reaction in terms of collision theory

Answer 1

Reactions occur when reactant particles collide with sufficient energy called activation energy

Question 2

what factors affect the rate of chemical reactions?

Answer 2

• temperature
• concentration of a solution
• pressure
• surface area
• catalyst

Question 3

what does an increase in temperature do to the rate of the reaction?

Answer 3

• increase in KE
• more particles with E ≥ Ea
• more successful collision per unit time
• increase R.o.R.

Question 4

what does an increase in concentration of a solution do to the rate of the reaction?

Answer 4

• increase in particles per unit volume
• more successful collisions per unit time
• increase R.o.R.

Question 5

what does an increase in pressure of a gas do to the rate of the reaction?

Answer 5

• increase in particles per unit volume
• more successful collisions per unit time
• increase R.o.R.

Question 6

what does increasing the surface are of solid reactants do to the rate of the reaction?

Answer 6

• increase in exposed molecules
• more successful collisions per unit time
• increase R.o.R.

Question 7

what does using a catalyst do to the rate of the reaction?

Answer 7

• provides an alternate pathway with lower Ea
• requires less energy for the reaction to occur
• more successful collisions per unit time
  = as more particles have => energy than Ea
• increase R.o.R.

Question 8

define activation energy

Answer 8

minimum energy needed to start a reaction

Question 9

define exothermic reaction

Answer 9

reaction where heat is given out
- temp increases

Question 10

define endothermic reaction

Answer 10

reaction where heat is taken in
- temp decreases