Question

How will you verify the law of conservation of mass experimentally?

Answer 1

Step 1: Definition of the law of conservation of mass

The law of conservation of mass states that the total sum of reactants is equal to the total sum of products.

Step 2: Identifying the requirements to verify the law

Conical flask, cork, small test tube with a thread tied to its end, Sodium chloride $\left(\mathrm{NaCl}\right)$ solution, Silver nitrate $\left({\mathrm{AgNO}}_3\right)$ solution, weighing scale

Step 3: Procedure to be performed to verify the law

1. Weigh the Conical flask, cork and test tube
2. Take 20g of Sodium chloride solution in the flask
3. Add 15g of Silver nitrate solution to the test tube and lower it into the flask by holding the thread
4. Fix the cork tightly on the mouth of the flask to hold the thread tightly, ensure the reactants don't mix
5. Weigh the apparatus, subtract the mass of flask, cork and test tube to get the mass of reactants (x grams)
6. Loosen the cork and thread, let the reactants mix
7. Results in the formation of a white precipitate of Silver chloride and Sodium nitrate solution.
8. Weigh the apparatus, subtract the mass of flask, cork and test tube to get the mass of products (y grams)

Diagram:

Result:

1. You will observe that the mass of reactants (x) is equal to the mass of products (y) i.e., 35 g.
2. This verifies the law of conservation of mass.