# Question ac033

Feb 18, 2017

The molar mass of a Substance = sum of molar masses of each element of the substance compound.

#### Explanation:

The molar mass or molecular mass is the mass of all the atoms present in a molecule in grams per mole.

To calculate the molar mass of a compound i.e. substance eg ${H}_{2}$$O$:

• First find out the atomic masses of each participating element in the compound from the periodic table eg:

$H = 1.008$ g/mol and $O = 15.999$ g/mol

• Count the number of atoms of the atoms in the compound for each element and multiply with the respective atomic weight, by this we get the molar mass of each element in compound eg:

$H = 2$ x $1.008 = 2.016$g/mol
$O = 1$ x $15.999$ = 15.999 g/mol

• Add the molar masses of each element

${H}_{2}$$O$ =$2.016 + 15.999$ = $18.015$ g/mol