The unknown of this problem is the experimental percent of water in the compound in order to remove the water of hydrogen, given the following:
Mass of crucible, cover and contents before heating 23.54 g
Mass of empty crucible and cover 18.82 g
Mass of crucible, cover, and contents after heating to constant mass 20.94 g
In order to get the answer, determine the following:
Mass of hydrated salt used = 23.54 g – 18.82 g = 4.72 g
Mass of dehydrated salt after heating = 20.94 g – 18.82 g = 2.12 g
Mass of water liberated from salt = 4.72 g – 2.12 g = 2.60 g
Then solve the percent of water in the hydrated salt by:
% water = (mass of water / mass of hydrated salt) x 100
% water = 2.60 g / 4.72 g x 100
% water = 55.08 % in the compound
