Question

In a experiment to determine the percentage of purity of a sample of sodium carbonate, 2.15g of the sample reacted completely with 40cm³ of 0.5m sulphuric (iv) acid

1. Calculate the number of moles of Sodium Carbonate that reacted 
2. Determine the percentage of Sodium Carbonate in the sample (Na=23,C=12,0=16
3. Name two industrial uses of Sodium Carbonate

Answer 1

1. Moles of H₂SO₄ that reacted = ⁴⁰/₁₀₀ × 0.5 =0.02
   Moles of Na₂CO₃ that reacted =0.02 
                                                  Mole ratio Na₂CO₃: H₂SO₄  1:1
2. Mass=Moles × FM
          =0.02 ×106
          =2.12g
   Percentage of purity = ^2.12/_2.15 ×100                               
                                     =98.6%
3.  
   1. Water softening
   2. Manufacture of glass
   3. making of soap
   4. Making of sodium hydrogen Carbonate-baking Powder