Chemistry
Answer
Sodium hydrogen carbonate crystals:
Method of preparation: By passing carbon dioxide gas into a cold solution of sodium carbonate.
Reaction:
Na2CO3 + CO2 + H2O ⟶ 2NaHCO3
Procedure:
- Dissolve 5 grams of anhydrous sodium carbonate in about 25 cm3 of distilled water in a flask.
- Cool the solution by keeping the flask in a freezing mixture.
- Pass carbon dioxide gas in the solution.
- Crystals of sodium bicarbonate will precipitate out after some time.
- Filter the crystals and dry it in the folds of filter paper.
Related Questions
How would you prepare copper sulphate crystals from a mixture of charcoal and black copper oxide.
How would you prepare zinc sulphate crystals from zinc dust (powdered zinc and zinc oxide).
How would you prepare calcium sulphate from calcium carbonate.
The following is a list of methods for the preparation of salts:
A — direct combination of two elements
B — reaction of a dilute acid with a metal
C — reaction of a dilute acid with an insoluble base
D — titration of a dilute acid with a solution of soluble base.
E — reaction of two solutions of salts to form a precipitate.
Choose from the list A to E, the best method of preparing the following salts by giving a suitable equation in each case:
- Anhydrous ferric chloride
- Lead chloride
- Sodium sulphate
- Copper sulphate