Chemistry
Grade-9
Easy
Question
What is the percentage mass of water present in washing soda crystal?
- 60
- 61
- 61.6
- 62.9
Hint:
One mole of washing soda has 10 molecules of water of crystallization.
The correct answer is: 62.9
The chemical formula of washing soda is Na2CO3.10H2O. Washing soda has 10 molecules of water of crystallization.
Mass of one mole of washing soda crystal is 286g.
The percentage mass of water present in washing soda crystal = (180
286)
100% = 60%
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