Question

What is the percentage of water in the following compound?
Sodium carbonate decahydrate, Na2CO3 • 10H2O
% by mass H2O

Answer 1

M(Na2CO3•10H2O)=23*2+12+16*3+180=286g/mol
So lets take 1 mol of this compound
m(comp)=286 gram
m(H2O)=180 gramm
w(h2o)=180/286=0.6293(62.93%)
Answer 62.93% water

Answer 2

Answer:

63.0

Explanation: