Question

Fill in the blanks 

(a) In a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is called ————. 

(b) A group of atoms carrying a fixed charge on them is called ————. 

(c) The formula unit mass of Ca₃ (PO₄)₂ is ————. 

(d) Formula of sodium carbonate is ———— and that of ammonium sulphate is ————.

Answer 1

(a) Law of conservation of mass 

(b) Polyatomic ion 

(c) (3 × atomic mass of Ca) + (2 × atomic mass of phosphorus) + (8 × atomic mass of oxygen) = 310 

(d) Na₂ CO₃ ; (NH₄)₂ SO₄