Students place 4 g of calcium carbonate with 2.92 g of hydrochloric acid. Class 9

Students place 4 g of calcium carbonate with 2.92 g of hydrochloric acid. Class 9

Question 1.

Students place 4 g of calcium carbonate with 2.92 g of hydrochloric acid in closed container. After the reaction is over, they measured 1.76 g of carbon dioxide, 0.72 g of water and 4.44 g of calcium chloride. Verify Law of conservation of mass is obeyed

Answer:

Law of conservation of mass states that mass of reactants = mass of products in a chemical reaction

Mass of reactants = mass of calcium carbonate + mass of hydrochloric acid - 4 + 2.92 = 6.92 g

Mass of products = mass of carbon dioxide + mass of water + mass of calcium chloride

mass of reactants = mass of products

Law of conservation of mass is obeyed.

Question 2.

12 g of carbon combines with 32 g of oxygen to form 44 g of carbon dioxide as per equation. Class 9

Carbon + Oxygen → Carbon dioxide

If 2.4 g of carbon reacts completely with oxygen, how much carbon dioxide is produced?

Answer:

12 g of carbon combines with 32 g of oxygen = 44 g of carbon dioxide

1 g of carbon = [latex]\frac {44}{12}[/latex] g of carbon dioxide. 2.4 g of carbon = [latex]\frac {44}{12}[/latex] × 2.4 g of carbon dioxide = 8.8 g of carbon dioxide