C H E M I S T R Y A N S W E R SC H E M I S T R Y A N S W E R S

11 Acids and bases

1 X is more acidic than Y.

2 C

3 Put a known volume of alkali into a fl ask.

Add indicator to the alkali.

Add acid from a burette, until the indicator changes colour.

Note the volume of acid used.

Repeat without the indicator, adding exactly the same volume of acid.

Evaporate to remove the water.

4 magnesium carbonate nitric acid magnesium nitrate water carbon dioxide

magnesium carbonate hydrochloric acid magnesium chloride water carbon dioxide

magnesium oxide sulfuric acid magnesium sulfate water

magnesium sulfuric acid magnesium sulfate hydrogen

magnesium hydroxide hydrochloric acid magnesium chloride water

magnesium oxide nitric acid magnesium nitrate water

5 to neutralise acidity in the soil

6 potassium

7 From top to bottom:

MgO (s), Fe (s), NaHCO3 (s), KOH (aq), Fe2O3 (s)

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C H E M I S T R Y A N S W E R SC H E M I S T R Y A N S W E R S

8 dinitrogen oxide - neutral oxide

carbon dioxide - acidic oxide

sodium oxide - soluble basic oxide

aluminium oxide - amphoteric oxide

iron(II) oxide - insoluble basic oxide

9 CH3COOH (aq) much less than 100%

H (aq) CH3COO (aq)

10 Barium sulfate is insoluble in water. It can be prepared by adding a solution of sodium sulfate to a solution of barium nitrate.

The mixture is fi ltered to remove the barium sulfate, which is then rinsed with distilled water.

The sodium ions and nitrate ions are spectator ions, and remain in solution.