Question

How would you calculate the molar mass of water?

Answer 1

Molar mass:-

• Molar mass of a compound is the mass of that compound present in 1 mole.
• It is the combined atomic masses of all the individual elements present in that molecule.
• Unit of molar mass is$\mathrm{g}{\mathrm{mol}}^{-1}$.

Molar mass of Water:-

Step 1: Calculate the molar mass of water

We know that molar mass of 1 mole of Hydrogen is $1\mathrm{g}{\mathrm{mol}}^{-1}$

and, molar mass of 1 mole of Oxygen is $16\mathrm{g}{\mathrm{mol}}^{-1}$

We know that the chemical formula of water is ${\mathrm{H}}_2\mathrm{O}$

$\therefore$molar mass of water is

$$\begin{gathered} {\mathrm{H}}_2\mathrm{O}=2\times 1+16 \\ =2+16 \\ 18\mathrm{g}{\mathrm{mol}}^{-1} \end{gathered}$$

Therefore, molar mass of water is$18\mathrm{g}{\mathrm{mol}}^{-1}$.