Question

Pepper designs an experiment to demonstrate the Law of Conservation of Mass. She dissolves 25 g of salt into 100 g of water in a beaker. She heats the water to boiling until it is all evaporated and captures the steam. The salt is left behind in the bottom of the beaker. Pepper records her results in the table below.

Water Salt Water + salt
Mass before 100 g 25 g W
Mass after 87 g 22 g X
Mass difference 13 g 3 g Y

What number does Y represent and what conclusion can be drawn from her results?

Answer 1

salt(before) = 25g W

salt(after) = 22gW

difference = 25 - 22 = 3gW