Reaction Rates

Question 1

Rate of reaction

Answer 1

Measures how fast a reactant is being used up or how fast a product is being formed
Defined as a change in conc of reactant/ product in given time

Question 2

How does the concentration of product increase over time

Answer 2

R of r, fastest, high concentration of reactants forming product
Slows down as reactants are used up, conc goes down
R of r=0 reactant used up conc stops changing, parallel to x

Question 3

Factors that affect r of r

Answer 3

Conc/ pressure (gas)
Temp
Catalyst
SA of solid reactants

Question 4

Collision theory

Answer 4

2 particles must collide for a reaction to occur

Question 5

Criteria for effective collisions

Answer 5

Correct orientation

Sufficient energy to overcome activation energy barrier of reaction

Question 6

Concentration and rates of reaction

Answer 6

Increase conc, increase no if particles in same volume
Particles closer together, collide more frequently
More effective collisions, increase r of r

Question 7

Pressure and r of r

Answer 7

Increase pressure, same no of particles in smaller volume
Particles closer together, collide more frequently
More effective collisions, r of r increases

Question 8

Following progress of reaction

Answer 8

Monitoring removal of reactant, decrease in conc

Following formation of product, increase in conc

Question 9

Reactions that produce gas

Answer 9

Monitor volume of gas produced at regular time intervals, gas collection
Monitoring loss of mass of reactants with balance
Find rate of reaction with tangents

Question 10

Reactions that lose mass

Answer 10

Monitor mass change at regular time intervals

Place cotton wool to avoid acid spitting and allow gas to leave