Explain this Activity step by step
Answers
Explanation:
AIM
To verify the law of conservation of mass in a chemical reaction,
MATERIALS REQUIRED
Barium chloride (BaCl2.2H20), sodium sulphate (Na2SO4.10H2O), distilled water, two beakers (100 mL), one beaker (150 mL), physical balance, spring balance (0-500 g), polythene bag, two watch glasses and a glass rod.
THEORY
During a chemical reaction, the mass of the reactants is equal to the mass of the products.
Mass can neither be created nor be destroyed.
It can be demonstrated using a precipitation reaction between BaCl2 (aq) and Na2SO4(aq).
The reaction involved is
CBSE Class 9 Science Practical Skills - Law of Conservation of Mass 1
According to the law of conservation of mass,
Mass of reactants (barium chloride + sodium sulphate) = Mass of products (barium sulphate+ sodium chloride).
PROCEDURE
Pour 50 mL distilled water in two 100 mL beakers.
Using the physical balance, weigh two watch glasses.
Weigh 3.6 g of BaCl2.2H20 in a watch glass of known mass and dissolve it in a beaker containing 50 mL distilled water and label it ‘A’.
Similarly, weigh 8.05 g of Na2SO4.10H2O in another watch glass of known mass and dissolve it in the other beaker containing 50 mL distilled water. Label it ‘B’.
Weigh the 150 mL beaker using spring balance and polythene. Label it ‘C’.
Mix solutions of beaker ‘A’ and ‘B’ together in beaker ‘C’. Mix the contents using a glass rod.
A white precipitate due tc the formation of barium sulphate (BaSO4) appears in the beaker ‘C’.
Weigh the beaker containing the reaction mixture again to find out the mass of products formed.
Compare the masses of the contents before ana after the reaction.
