Q3. *Measure the rate of production of oxygen from hydrogen peroxide

Question 1

What acts as the catalyst for this reaction?

Answer 1

Manganese dioxide

Question 2

What is the role of manganese dioxide in this experiment?

Answer 2

It acts as a catalyst to speed up the decomposition of the hydrogen peroxide

Question 3

What chemicals are required?

2

Answer 3

Hydrogen peroxide (‘20 volume’)

Manganese dioxide

Question 4

What is the formula for manganese dioxide?

Answer 4

MnO2

Question 5

What is the formula for hydrogen peroxide?

Answer 5

H2O2

Question 6

What is MnO2?

Answer 6

Manganese dioxide

Question 7

What is H2O2?

Answer 7

Hydrogen peroxide

Question 8

Give the formula for this equation.

Answer 8

H2O2 —MnO2—> H2O + 1/2 O2

Question 9

What is the first step of this experiment?

Answer 9

Fill a trough to about half its capacity with water and invert a 250 cm cubed graduated cylinder(filled with water) over it as shown

Question 10

What should the trough be filled with?

Answer 10

It should be filled to half its capacity with water

Question 11

How should you set up the graduated cylinder?

Answer 11

Invert the 250 cm cubed graduated cylinder filled with water over the trough

Question 12

What is the second step of the experiment, the graduated cylinder has been set up?

Answer 12

Place 50 cm cubed of ‘20 volume’ hydrogen peroxide solution in the conical flask

Question 13

How much of the ‘20 volume’ hydrogen peroxide should be placed in the conical flask?

Answer 13

50 cm cubed

Question 14

What is the third step of the experiment, the hydrogen peroxide has been added to the conical flask?

Answer 14

Place the end of the delivery tube (already connected to the mouth of the graduated cylinder) under the graduated cylinder

Question 15

Where is the delivery tube connected to?

Answer 15

The mouth of the conical flask and under the graduated cylinder

Question 16

What is the fourth step of the experiment, the delivery tube has been set up?
(2)

Answer 16

When ready to begin, add a small amount (spatula tip full) of manganese dioxide to the hydrogen peroxide

Then immediately stopper the conical flask and start the stopclock/stopwatch

Question 17

How much of the manganese dioxide should be added?

Answer 17

A spatula tip full

Question 18

Where should the manganese dioxide be added to?

Answer 18

The conical flask of hydrogen peroxide

Question 19

What two things should be done immediately once the catalyst is added?

Answer 19

Stopper the conical flask

Start the stopclock/stopwatch

Question 20

What is the fifth step of the experiment, the catalyst has been added and the clock has been started?

Answer 20

At half-minute intervals, read the volume of gas in the graduated cylinder and note the results

Question 21

At what intervals should the volume of gas be recorded?

Answer 21

At half-minute intervals

Question 22

What is the sixth step of the experiment, the volume of gas is being recorded?

Answer 22

Continue measuring the volume of gas until the reaction is over, i.e. when the volume of gas evolved remains the same

Question 23

When should you stop the experiment?

Answer 23

When the reaction is over

Question 24

How do you know when the reaction is over?

Answer 24

When the volume of gas evolved remains the same

Question 25

What is the seventh step of the experiment, the reaction has just ended?

Answer 25

Plot a graph of volume of oxygen (y-axis) against time (x-axis)

Question 26

What should be on the x-axis of your graph?

Answer 26

Time

Question 27

What should be on the y-axis of your graph?

Answer 27

Volume of oxygen