Formula of hydrated sodium carbonate : Na₂CO₃.10H₂O, so moles of water in one mole of hydrated salt = 10
Hydrate is a compound that binds water (H₂O), usually in the form of crystals/ solids
If these compounds are dissolved in water or heated, the hydrates can decompose:
Example: X.YH₂O (s) → X (aq) + YH₂O (l)
The formula for the hydrated compound contains: YH2O
The mole ratio shows the ratio of the coefficients of the hydrate compound
10.45 hydrated sodium carbonate(Na₂CO₃.xH₂O) were heated until 3.87 of 3.87of anhydrous (Na₂CO₃) remained, so
mass H₂O released :
[tex]\tt 10.45-3.87=6.58~g[/tex]
mass Na₂CO₃ = 3.87 g
mol ratio Na₂CO₃(MW= g/mol) : H₂O(MW=18 g/mol) =
[tex]\tt \dfrac{3.87}{105,9888}\div \dfrac{6.58}{18}=0.0365\div 0.3655=1\div 10[/tex]