Question

A 15.67 g sample of a hydrate of magnesium carbonate is heated, and the water is driven off. If the anhydrous residue weighs 10.48 g, what is the mass of the water in the hydrate?

A. 5.19 g
B. 10.48 g
C. 15.67 g
D. 25.15 g

Answer 1

To find the mass of water in the hydrate, subtract the mass of the anhydrous residue (10.48 g) from the initial mass of the hydrate (15.67 g), resulting in 5.19 g of water lost. Option A: 5.19 g is the correct option.

Step-by-step explanation:

The mass of the water in the hydrate can be found by subtracting the mass of the anhydrous residue from the initial mass of the hydrate. Starting with a 15.67 g sample of hydrate, after heating, you have 10.48 g of anhydrous magnesium carbonate.

The mass of water lost would be the initial mass minus the mass of the anhydrous residue:

Mass of water = Initial mass of hydrate - Mass of anhydrous residue

Mass of water = 15.67 g - 10.48 g = 5.19 g

Therefore, Option A: 5.19 g is the mass of the water in the hydrate, and this will be our correct option in the final answer.