An 8.10-g sample of hydrated magnesium carbonate is heated. It has a mass of 4.94 g after heating. What is the percentage by mass of water in the hydrate?

3.16%
17.6%
39.0%
61.0%

Respuesta :

8.10-4.94=3.16=mass of water
3.16/8.10 X 100 = 39.0%

C or 3rd option: 39.0%