Question

Question #422bb

Answer 1

The % mass is 4%.

The density of water is 1g/`cm^3` so 240 `cm^3` of water has a mass of 240g.

The mass of hydrated sodium carbonate is 10g so the total mass of solute + solvent = 240 + 10 = 250g

So the % mass of hydrated sodium carbonate =10/250 x 100 = 4%.