2P05 - When dilute acids meet carbonates

1. Dilute acid reacts with a carbonate to produce carbon dioxide gas.


2. Metal carbonate  + Acid --> Salt + Water + Carbon Dioxide


3.  Differences:
(a) 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 experiement.


(b) A white precipitate is formed in limewater in the first experiment while there is no visible change in this experiment.


(c) The damp blue litmus paper turned red in the first experiment, while there is no visible change in this experiment.


Explanation:


The reaction between calcium carbonate and sulfuric acid is imcomplete. The product, calcium sulfate 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 (you do not put the gas in limewater). If the gas is carbon dioxide, a white precipitate is formed. (You do not use the word "chalky")


5. a) Carbon dioxide is acidic.
    b) Bubble the sample of air through limewater. carbon dioxide gas in the air will react with limewater to form an insoluble product, calcium carbonate. Thus removing carbon dioxide from the air.


EXERCISE:


1a. Hydrochloric acid + calcium carbonate ---> calcium chloride + carbon dioxide + water
  b. CaCO₃ + 2HCl ---> CaCl₂ + CO₂ + H₂O


2a. Hydrochloric acid + sodium carbonate ---> sodium chloride + carbon dioxide + water
  b. Na₂CO₃ + 2HCl ---> 2NaCl + H₂O + CO<sub>2


3a.</sub> Potassium carbonate + Hydrochloric acid ---> potassium chloride + carbon dioxide + water
  _b. K2CO3 + 2HCl --> 2KCl + H2O + CO2


_{4a.  Calcium} carbonate + Nitric acid  _{--->Potassium nitrate + carbon dioxide + water
  b.}  2HNO3 + CaCO3 = Ca(NO3)2 + H2O + CO2


5a. Sodium carbonate + nitric acid ---> Sodium nitrate + carbon dioxide + water
  b. NaC03 + HNO3 ----> NaNO3 +H20 + CO2

6a. Potassium carbonate + Nitric acid ---> potassium nitrate + carbon dioxide + water

 b. K2CO3 + 2HNO3 ---> 2KNO3 + CO2 + H2O

7a. Calcium carbonate + Sulfuric acid ---> Calcium sulfate + carbon dioxide + water

 b. CaCO3 + H2CO4 = CaSO4 + CO2 + H2O 

8a.  Sodium carbonate + Sulfuric acid ---> Sodium sulfate + carbon dioxide + water 

 b.  Na2CO3 + H2SO4 => Na2SO4 + CO2 + H2O

9a. Potassium carbonate + Sulfuric acid ---> Potassium sulfate + carbon dioxide + water 

  b. K2CO3 + H2SO4 → K2SO4 + CO2 + H2O

10a. Sodium carbonate + Ethanoic acid ---> Sodium ethanoate + carbon dioxide + water 

  b.  Na₂CO_{3 +} 2CH3COOH ---> 2NaC2H3O2 + CO2 +H2O

11a. Potassium carbonate + Ethanoic acid ---> Potassium ethanoate + carbon dioxide + water

   b. K₂CO_{3 +} 2CH3COOH ---> 2CH₃CO₂K + CO2 + H2O

12a. Calcium carbonate + Ethanoic acid ---> Calcium ethanoate + carbon dioxide + water 

   b. CaCO_{3 +} 2CH3COOH ---> Ca(C₂H₃O₂)₂ + CO2 + H2O


Done by:

Bryan Chia Jun Qing (5)

Koh Kai Jie (14)

Soh Han Qiang (23)

Yap Jun Lin (32)