Q Observation when carbonate is added to acid.
Effervescence of colourless and odourless gas was observed.
Q Lime water
A white precipitate was formed
Q Damp litmus paper
Damp blue litmus paper turns red
Q conclusion
1.
Dilute acid reacts with a carbonate to produce carbon dioxide gas
2.
Acid + carbonate = salt + water + carbon dioxide
3.
Differences:
Effervescence of colourless and odourless gas which formed a white precipitate in limewater was observed in the first experiment, while no gas was evolved in this experiment
A white precipitate is formed in limewater in the first experiment, while there is no visible change in this experiment
The damp blue litmus paper turned red in the first experiment, while there is not visible change in this experiment.
Explanation:
The reaction between calcium carbonate and sulfuric acid is incomplete. The product, calcium sulfide, is insoluble in water. It will form a coating around the insoluble calcium carbonate. Hence, prevent further reaction from taking place.
4.
Bubble the gas through limewater. If the gas is carbon dioxide, a white precipitate will be formed.
5 (a) acidic
(b) Bubble the sample of air through limewater. Carbon dioxide gas in the air will react with limewater (calcium hydroxide) to form an insoluble product, calcium carbonate. Thus, removing the carbon dioxide from the air.
Exercise
1 (a) calcium carbonate + hydrochloric acid--> calcium chloride + carbon dioxide+ water
CaCO3 + 2HCl --> CaCl2 + CO2 + H2O
Sodium carbonate + hydrochloric acid --> sodium chloride + water + carbon dioxide
Na2CO3 + 2HCl --> 2NaCl + H2O + CO2
Potassium carbonate + hydrochloric acid--> potassium chloride + water + carbon dioxide
K2CO3 + 2HCl --> 2KCl + H2O + CO2
Calcium carbonate + nitric acid--> calcium nitrate + water + carbon dioxide
CaCO3 + 2HNO3 --> Ca(NO3)2 + H2O + CO2
Sodium carbonate + nitric acid --> sodium nitrate + water + carbon dioxide
Na2CO3 + 2HNO3 --> 2NaNO3 + H2O + CO2
Potassium carbonate + nitric acid --> potassium nitrate + water + carbon dioxide
K2CO3 + 2HNO3 --> 2KNO3 + H2O + CO2
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