A7.028 gram sample of a sodium sulfate hydrate is heated. after driving off all the water, 3.100 grams of the anhydrous salt is left. what is the name of the hydrate?

Explanation:

Given that:-

Mass of the hydrated salt = 7.028 g

Mass of the anhydrous salt = 3.100 g

Mass of water eliminated = Mass of the hydrated salt - Mass of the anhydrous salt = 7.028 - 3.100 g = 3.928 g

Moles of water:

Mass of water = 3.928 g

Molar mass of = 18 g/mol

The formula for the calculation of moles is shown below:

Thus, moles are:

Moles of anhydrous salt:

Amount = 3.100 g

Molar mass of = 142.04 g/mol

Thus, moles are:

The simplest ratio of the two are:

=0.02182 :  0.2212 = 1 : 10

Hence, the formula for hydrate is:-

the answer would be c