Measuring Rates of Reaction

Question 1

Rate of Reaction equation =

Answer 1

Amount of reactant used or amount of product formed / Time

Question 2

Give 3 examples of different ways the rate of reaction can be measured?

Answer 2

• Precipitation
• Change in Mass
• Volume of gas given off

Question 3

Describe how to measure the rate of reaction using the precipitation method .

Answer 3

• mix the 2 reactants
• place flask on a piece of paper with a mark on it
• observe mark through mixture and measure how long it takes for the mark to be obscured
• faster disappears = faster the reaction

Question 4

What type of solution does the precipitation method require ad why?

Answer 4

2 see-through Solutions - so when precipitate produced —> clouds the solution

Question 5

Why is the precipitation method not always accurate?

Answer 5

The result is subjective - different people might not exactly agree on exactly when mark ‘disappears’

Question 6

Describe how to measure the rate of reaction using the Change in Mass method .

Answer 6

• measure rate of reaction that produces a gas using a mass balance
• as gas released —> lost mass measured on balance
• quicker the reading drops = faster the reaction
• reactions finished when reading stops changing

Question 7

What are the possible dangers when carrying out the change in mass experiment and what safety precautions should be taken?

Answer 7

• releases gas produced into the room
• if gas is harmful* —> do experiment in fume cupboard

Question 8

Describe how to measure the rate of reaction using the volume of gas given off method .

Answer 8

• use gas syringe to measure volume of gas given off
• more gas given off within set time interval = faster the reaction
• reaction finished when no more gasproduced

Question 9

What are precautions that should be taken when carrying out the volume of gas given off experiment?

Answer 9

• use the right size gas syringe
• if reaction too vigorous -> could blow plunger out of the end of the syringe