How would you calculate the molar mass of water?

The total sum of the masses of the atoms or elements present in the molecule is termed as molecular mass.

Calculation of Molar mass of a compound

We can find the molecular mass of the molecule by following the given substance:

• Identify the formula of the compound or molecule
• Using the formula determine the number of atoms present in each element of the compound or molecule
• Multiply the atomic weight of each element with the number of atoms of that particular element
• Similarly, do it for all the elements in the molecule or compound
• Add up all the values obtained in the above step
• Then add the unit as grams/mole you will get the molecular mass of the substance

Molar mass of water

One mole of H2O is made up of 2 moles of hydrogen atoms and 1 mole of oxygen atom.

Molar mass of atoms

Mass of 1 mole of Hydrogen atoms= 1 g /mol

Mass of 1mole of Oxygen atoms = 16 g/mol

Mass of two moles of Hydrogen atoms = 2x 1 g/mol = 2 g/mol.
Mass of one mole of Oxygen atoms = 1 x 16 g /mol

On adding all the above-obtained values we get,

Mass of one mole of water = 2 g/mol + 16 g/mol = 18 g/mol.

Molar mass of water = 18g/mol