Question

volume of co2 obtained at stp by the complete decomposition of 9.85g of na2 co3 is........?

Answer 1

Na2CO3⇒ Na2O + CO2
1 mole of sodium carbonate give 1 mole of carbon dioxide.
as 105.98g sodium carbonate gives 44.01g carbon dioxide
therefore, 9.85 g sodium carbonate gives = 9.85 × 44.01 =4.09 g of CO2 105.98 
Moles of CO2 mole = weight =4.09/44.01= 0.092 mole
Molar mass
1 mole of gas = 22.4 L gas

Therefore,0.092 mole of CO2 = 22.4 × 0.092 = 2.06 L CO2.