Question

An 8.24 gram sample of a hydrated salt is heated until it has a constant mass of 6.20 grams. What was the percent by mass of water contained in the original sample

Answer 1

Answer:

32.9%

Explanation:

The mass of water present in the original sample can be calculated by the substraction:

• m H₂O = sample mass before heating - sample mass after heating

• m H₂O = 8.24 g - 6.20 g = 2.04 g

The percent by mass of water can be calculated with the formula:

• Water Mass / Original Sample Mass * 100 %

• $\frac{2.04}{6.20}$ * 100% = 32.9%