Asolid hydrate weighing 2.682 grams was heated to drive off the water. a solid anhydrous residue remained, which weighed 1.420 grams. calculate the percent of water in the hydrate

47.05%

We are given;

Mass of a solid hydrate = 2.682 grams

Mass of the solid anhydrous residue = 1.420 grams

We are required to determine the percent of water hydrate;

Mass of water = Mass of the solid hydrate - mass of the anhydrous residue

Therefore;

Mass of water = 2.682 g - 1.420 g

                       = 1.262 g

% water in the hydrate = (mass of water ÷ mass of the solid hydrate)×100%

Therefore;

% water in the hydrate = (1.262 g ÷ 2.682 g) × 100%

                                      = 47.05%

Hence, the percent water in the hydrate is 47.05%