Page 23 - ICSE Chemistry 8

Activity 1.4

Aim: To show that the total mass of reactants is equal to the total mass of products
in a chemical reac on between barium chloride and sodium sulphate
Materials required: A conical fl ask, a test tube, cork, barium chloride, sodium
sulphate, measuring scale

Procedure
• Take a conical fl ask and prepare a solu on of barium chloride and water in
the fl ask.
• Take a test tube and prepare a solu on of sodium sulphate in it.

• Slide the test tube which is half fi lled with sodium sulphate solu on carefully
inside the conical fl ask which contains barium chloride solu on.
• Seal the conical fl ask with a cork ghtly.
• Measure the mass of the fl ask with its contents using a measuring balance.

• Now li the fl ask in your hand and carefully turn it upside down.
Observa on: The sodium sulphate solu on pours out of the test tube and gets
mixed with the barium chloride solu on. The reac on take place between sodium
sulphate and barium chloride, and in turn, barium sulphate and sodium chloride
are formed.

BaCl 2 + Na SO BaSO 4 + 2NaCl
4
2
Barium chloride Sodium sulphate Barium sulphate Sodium chloride
Procedure

• Using the measuring balance once more, measure the mass of the fl ask and its contents.
Observa on: The mass of the conical fl ask and its cons tuents before the reac on is equal to the mass of
the fl ask and its cons tuents a er the reac on.

Conclusion: This shows that the total mass of the reactants remains same as the total mass of the products
in a chemical reac on.

Note: Barium chloride is a toxic chemical and direct contact with barium chloride should be avoided.

Take a Break!

Fill in the blanks.
1. The ____________________ states that mass can neither be created nor destroyed.

2. The ________________ of ma er and the ________________ occupied by the ma er may vary
within a system but the mass remains ________________.
3. The total mass during a chemical reac on remains ________________.

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