Q.
19 g of a mixture containing NaHCO3 and Na2CO3 on complete heating liberated 1.12 L of CO2 at STP. The weight of the remaining solid was 15.9 g. What is the weight (in g) of Na2CO3 in the mixture before heating?
Molecular weight of NaHCO3=23+1+12+48=84 Molecular weight of Na2CO3=46+12+48=106 Hence, total weight =84+106=190∵ In 190 g of a mixture, weight of NaCO3 is =106 ∴ In 19 g of a mixture weight of Na2CO3=190106×19=10.6g