# Washing Soda Has the Formula Na2co3.10h2o.What is the Mass of Anhydrous Sodium Carbonate Left When All the Water of Crystallization is Expelled by Heating 57.2 G of Washing Soda? - Chemistry

Sum

Washing soda has the formula Na2CO3.10H2O.What is the mass of anhydrous sodium carbonate left when all the water of crystallization is expelled by heating 57.2 g of washing soda?

#### Solution

$\ce{Na2CO3.10H2O ->[\Delta] Na2CO2 + 10H2O}$

molecular weight of washing soda is 286.14g
molecular weight of sodium carbonate is 106g
286.14g of Na2CO3. 10H2O forms 106g of sodium carbonate on heating 57.2 g of Na2CO3. 10H2O forms = 106 X 57.2/286.14 = 21.2g

Concept: Relationship Between Vapour Density and Relative Molecular Mass
Is there an error in this question or solution?

#### APPEARS IN

Frank ICSE Class 10 Chemistry Part 2
Chapter 5 Mole Concept And Stoichiometry
Exercise | Q 5.2 | Page 118