Question

Write an experiment to show law of conservation of mass. Taking barium chloride & sodium sulphate as examples.​

Answer 1

Answer:

Barium chloride reacts with sodium sulphate to form Barium sulphate and sodium chloride. Then, according to the law of conservation of mass The total mass of the reactants is equal to the total mass of products.

Hence, BaCl2  + Na2 SO4  → BaSO4  + 2NaCl

Explanation:

Procedure :-

1. Take 5ml of sodium sulphate solution in a measuring cylinder and pour it into a conical flask.

2. Take about 5 ml of barium chloride solution in another measuring cylinder and pour it into a 10ml test tube.

3. Tie the test tube using a thread and hang the test tube in the conical flask carefully, so that the solutions do not mix with each other.

4. Put a cork in the mouth of the flask so that the thread holding the test tube is held firmly in place.

5. Carefully weigh the flask on a weighing balance and note the reading.

6. Tilt and swirl the flask so that barium chloride solution in the test tube spills and mixes with sodium sulphate solution in the flask and forms a white coloured precipitate of barium sulphate (BaSO4)and an aqueous solution of sodium chloride (NaCl).

7. Wait for 10 min. to complete the reaction. The white precipitate settles down to the bottom of the flask.

8. Weigh the contents of the flask again and note the reading.

Observation :-

1.Mass of total apparatus + Mass of reactants = (M + m1) g

2.When barium chloride solution in the test tube mixes with the sodium sulphate solution in the conical flask, a white precipitate is formed.

3.Mass of total apparatus + Mass of products = (M + m2) g

m1 = m2 (Hence, law of conservation of mass proved)