A sample of unknown hydrate, AC-XH20, has a mass of 1.000 g before heating and a mass of 0.781 g after heating. If the molar mass of the anhydrous compound (AC) is
195.5 g/mol, what is the water of crystallization for the formula of the unknown
hydrate?
Type your work for partial credit.
Answer choices: 2, 3, 5, or 6.

The water of crystallization for the formula of the unknown  hydrate is 2.

Explanation:

Mass of an unknown hydrate = 1.000 g

Molar mass of hydrate = 195.5 g/mol

MOles of unknown hydrate =

Mass of hydrate after heating = 0.781 g

Mass of water lost due to heating = x

Moles of water lost =

1 Mole of hydrate has x moles of water and 0.00512 moles of hydrate has 0.0122 moles of water then we can write:

The water of crystallization for the formula of the unknown  hydrate is 2.

first one is the correct answer