Question

Sam records the mass of his evaporating dish as 6.488 g. He records the mass of the evaporating dish and the sample of hydrate as 19.72 g. After heating the sample in the evaporating dish to constant weight, the mass of them combined is 11.344 g. How many moles of water were removed from the sample by the heating process?

Answer 1

`0.46` moles of water were removed from the sample by the heating process

Step-by-step explanation:

Given

Mass of the evaporating dish
`= 6.488` grams

Mass of the sample of hydrate
`= 19.72` grams

Mass of the sample and dish after heating
`= 11.344` grams

The weight of water removed through evaporation

`= 19.72 - 11.344 = 8.376` grams

Weight of one mole of water
`= 18` grams

Number of moles of water in
`8.376` Grams of water is equal to

`(8.376)/(18) = 0.46` moles