Kinetics

Question 1

what 2 ways can a reaction be measured

Answer 1

• by monitoring rate of formation of products
• by monitoring rate of decline of reactants

Question 2

give some examples of ways that a reaction can be measured

Answer 2

• gas syringe (vol. of gas)
• colorimeter
• pH meter
• pressure

Question 3

what is collision theory used to do

Answer 3

explain how different factors can affect the rate of a chemical reaction

Question 4

explain the 3 main ideas behind collision theory

Answer 4

• particles must collide if they are to react
• collisions must be equal or greater than the required activation energy
• collisions must have the correct orientation

Question 5

in terms of collision theory what are 3 ways that a reaction be made to speed up

Answer 5

• increase frequency of collisions
• increase energy of particles so a greater proportion passes activation energy or greater
• lower the activation energy so more collisions possess this lower activation energy

Question 6

how can the gradient of a reaction curve be calculated

Answer 6

change in y / change in x

Question 7

using collision theory explain why the rate of reaction slows over time

Answer 7

as time passes there are less particles and there are less frequent collisions

Question 8

how does surface area affect reaction rate in terms of collision theory

Answer 8

smaller particles have a larger sa so more particles of solid reactant as exposed and available for collision

Question 9

why can naked flames cause a risk of explosion in saw and flour mills

Answer 9

very fine particles have a huge surface area which means that many reactant particles are in contact with oxygen in air - meaning a very fast combustion reaction can happen

Question 10

why does a higher conc. of solution react faster than a lower conc.

Answer 10

greater no. of particles in a given volume - leading to more frequent collisions