C4

Question 1

What can you use to test the pH of a substance? And what is it?

Answer 1

• An indicator- a dye that changes the colour of a solution according to the pH
• pH probe (electronic indicator)- gives you a number meaning its more accurate.

Question 2

What do metals and acids react together to make?

Answer 2

Salt+hydrogen.

Question 3

What do metal hydroxides and water react together to make?

Answer 3

Metal hydroxide+ hydrogen.

Question 4

What two things can oxidation mean?

Answer 4

The gain or oxygen and the loss of electrons

Question 5

What two things can reduction mean?

Answer 5

The loss of oxygen or the gain of electrons.

Question 6

What does electrolysis mean?

Answer 6

The splitting up with electricity.

Question 7

what do metal oxides and water react together to make?

Answer 7

salt+water

Question 8

what do acids and metal bases react together to make?

Answer 8

salt+water

Question 9

what do acids and metal carbonates react together to make?

Answer 9

salt+water+carbon dioxide

Question 10

describe an experiment you can do to make a pure salt?

Answer 10

1. heat sulphuric acid
2. stir in copper sulphate until it’s in excess (no more can be dissolved)
3. let it cool
4. filter solution to remove excess copper oxide
5. evaporate away the liquid until you have copper sulphate crystals. the size of the crystals depends on how quickly you evaporate it.

Question 11

what is the neutralisation equation?

Answer 11

H^+ + H^- <====>H20

Question 12

explain what the difference is between a strong acid and a weak acid

Answer 12

strong acids ionise completely in water however weak acids only ionise partially in water.

Question 13

what is an electrolyte?

Answer 13

a liquid that can conduct electricity