Question

How many grams of water would there be in 100.0g of hydrate? How many moles?

Answer 1

Answer: The mass of water present in given amount of hydrate is 36.68 grams and number of moles of water are 2.04 moles.

Explanation:

We are given:

Mass of hydrate = 0.946 grams

Mass of water present = 0.347 grams

We need to calculate the mass of water present in 100 grams of hydrate. By using unitary method, we get:

In 0.946 g of hydrate, the amount of water present is 0.347 g

So, in 100 g of hydrate, the amount of water present will be = $\frac{0.347g}{0.946g}\times 100g=36.68g$

Hence, the mass of water present in given amount of hydrate is 36.68 grams.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of water = 36.68 g

Molar mass of water = 18 g/mol

Putting values in above equation, we get:

$\text{Moles of water}=\frac{36.38g}{18g/mol}=2.04mol$

Hence, the number of moles of water are 2.04 moles.

Answer 2

The calculation for the amount of water present in the given amount of hydrate is shown below,
            amount water = (100 g hydrate) x (0.347 g H2O / 0.946 g hydrate)
                                  = 36.68 g
Thus, the amount of water present in the hydrate is approximately 36.68 g.