Question

The equation given below relates the manufacture of sodium carbonate (molecular weight of Na₂CO₃ = 106).

1. NaCl+NH₃+ CO₂+ H₂O→ NaHCO₃+NH₄Cl
2. 2NaHCO₃→ Na₂CO₃+H₂O + CO₂

Equations (1) and (2) are based on the production of 21.2 g of sodium carbonate.

(a) What mass of sodium hydrogen carbonate must be heated to give 21.2 g of sodium carbonate?

(b) To produce the mass of sodium hydrogen carbonate calculate in (a), what volume of carbon dioxide, measured at S.T.P. would be required?

Answer 1

(a) NaCl+NH₃+ CO₂ + H₂O → NaHCO₃+NH₄Cl

2NaHCO₃ → Na₂CO₃+H₂O + CO₂

From equation:

106 g of Na₂CO₃ is produced by = 168 g of NaHCO₃

So, 21.2 g of Na₂CO₃ will be produced by = 168 × 21.2/106

= 33.6 g of NaHCO₃

(b) For 84 g of NaHCO₃, required volume of CO₂ = 22.4 litre

So, for 33.6 g of NaHCO₃, required volume of CO₂ = 22.4 x 33.6/84

= 8.96 litre