Volume of gas produced PRACTICAL

Question 1

Describe how to investigate how changes in concentraton affect the rate of reaction

volume of gas practical

Answer 1

1. Using a measuirng cylinder pour 50cm^3 of hydrochloric acid into a connical flask
2. Attatch a bung and delivery tube to the connical flask
3. Now, pour water into a container and place a upturnded measuring cylinder filled with water into the container
4. Feed the delivery tube into the cylinder
5. Place a 3cm strip of magnesium into the connical flask, start the stopwatch
6. The reaction produces hydrogen which fills up the measuring cylinder
7. Every 10 seconds record te volume of hydrogen in the measuring cylinder until the hydrogen stops being produced. Stop the stopwatch
8. Repeat the experiment using different concentrations of hydrochloric acid

Question 2

Describe how you could make this experiment more accurate

Answer 2

Use a gas syringe

Question 3

Name a disadvantage of using a gas syringe to make this practical more accurate?

Answer 3

There may be some leakage of gas from the gas syringe, so we would collect and record less gas than there really was

Question 4

What error do people sometimes make when setting up this practical?

Answer 4

They put the delivery tube into the hydrochloric acid

This means that no hydrogen gas will be collected

Question 5

A student uses cotton wool as a stopper in this experiment.
Explain why there is a loss of mass in this investigation

[2 marks]

Answer 5

Gas is produced
and the gas escapes from the connical flask

Question 6

Describe another method (other than measuring the change in mass of the reactants), that could be used to find the rate of the reaction

[1 mark]

Answer 6

Collect gas in a gas syringe