Question

How many moles of water are present in 15.00 ml of water
that has a density of 0.9956 g/ ml.
MW for Hydrogen 1.00 g/ 1 mole; MW for Oxygen 16.00 g/ 1 mole

Answer 1

Answer : The moles of water present in solution are, 0.8297 moles.

Explanation :

First we have to calculate the mass of water.

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}$

$\text{Mass of water}=0.9956g/mL\times 15.00mL=14.934g$

Now we have to calculate the moles of water.

$\text{Moles of water}=\frac{\text{Mass of water}}{\text{Molar mass of water}}$

Molar mass of water = (2 × Molecular weight of hydrogen) + Molecular weight of oxygen

Molar mass of water = (2 × 1.00g/mol) + 16.00 g/mol

Molar mass of water = 18.00 g/mol

$\text{Moles of water}=\frac{14.934g}{18.00g/mol}$

$\text{Moles of water}=0.8297mol$

Therefore, the moles of water present in solution are, 0.8297 moles.