RATES OF REACTIONS

Question 1

for consistency how do chemists measure rates of reaction

Answer 1

as the change in concentration / time

Question 2

according to collision theory, what must be true for a collision of two particles to result in a reaction.?

Answer 2

correct orientation and sufficient energy to overcome activation energy.

Question 3

what is the effect of the addition of a catalyst to an equilibrium mixture?

Answer 3

• no visible effect on reaction mixture
• because catalyst will speed up RO forward and reverse reaction equally.
• it will speed up the rate at which equilibrium is established.

Question 4

define catalyst

Answer 4

a substance that speeds up a reaction without being used up by providing an alternative reaction-route with a lower Activation Energy

Question 5

effect of increasing concentration on the ROR?

Answer 5

• ROR generally increases because it increases number of particles in same volume leads to more effective collisions and an increased rate of reaction

Question 6

effect of increasing the pressure of a gas on ROR?

Answer 6

• reduce volume = same as increase pressure
• conc. of gas molecules increases as the same number of gas molecules occupy a smaller volume.
• closer gas molecules = more frequent collision = more effective collisions.

Question 7

What are the two ways of continuous monitoring when a gas is produced?

Answer 7

Gas collection at regular time intervals

reactant Mass loss use balance

Question 8

What is a way of utilising light to monitor rate?

Answer 8

Using a colourimeter.

Measuring the amount of light absorbed by a solution.