Topic 6The Rate and Extent of Chemical Change

Question 1

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

Answer 4

Question 5

Answer 5

Question 6

Give the name of the solvent used to dissolve the ions in this reaction.

Answer 6

Water

Question 7

A few drops of a colourless solution containing a high concentration of
thiocyanate ions (SCN–
) are added to the orange equilibrium mixture.
Explain the colour change observed.

Answer 7

Question 8

A water bath is set up at a temperature above room temperature.
When a test tube containing the orange equilibrium mixture is placed in the
water bath, the mixture becomes more yellow.
Explain what this shows about the energy change for the forward reaction. mixture.
Explain the colour change observed.

Answer 8

Question 9

Explain why a low pressure is used in stage 1.
Give your answer in terms of equilibrium.

Answer 9

Question 10

Answer 10

Question 11

The equilibrium mixture is cooled.
Explain what happens to the concentration of the pink cobalt compound

Answer 11

Question 12

More hydrochloric acid is added.
Explain what happens to the colour of the equilibrium mixture

Answer 12

Question 13

Answer 13

Question 14

The student measured the change in mass of the reactants.
Describe another method, other than measuring the change in mass of the reactions, that
the student could have used to find the rate of the reaction between marble chips and hydrochloric acid.

Answer 14

Question 15

Answer 15

I,ncreases

Question 16

Answer 16

Activation

Question 17

Answer 17

Question 18

Answer 18

Question 19

4

Answer 19

acid particles used up
so concentration decreases
so less frequent collisions
so rate decreases /