Question

Calculate the mass of solid sodium carbonate when 16.8 grams of sodium hydrogencarbonate is heated strongly until there is no further change. (3pts) 2NaHCO3(s) -- Na2CO3(s) + CO2 (g) +H2O (l) *

Answer 1

$2NaHCO_3 (heat) \to Na_2CO_3+CO_2+H_2O$

Moles of sodium hydrogen carbonate $=\frac{16.8}{23+1+12+16+16+16}=0.2$

Mole ratio, sodium hydrogen carbonate : sodium carbonate=2:1

Moles of sodium carbonate = $0.2/2=0.1$

Mass of sodium carbonate = no. of mole $\times$ molar mass=$0.1\times (23+23+12+16+16+16)=10.6g$