Question

The molar mass of ${{H}_{2}}O$ is:

Answer 1

Hint: ${{H}_{2}}O$ is the molecular formula used for water. Water is the lifeline of living organisms. It is generally a colorless, odorless, tasteless and liquid substance. Water covers 71% of the earth’s surface in the form of sea and oceans.

Complete Step by step solution: The term molar mass of a chemical compound can be defined as the mass of a sample of that compound divided by the amount of substance in that sample it is generally measured in moles. The molar mass is a bulk phenomenon. The molar mass is an average of many instances of the compound which often vary in mass due to the presence of isotopes.
The molar mass is an intensive property of the substance, meaning that substance does not depend on the size of the sample. The SI unit of molar mass is $Kgmo{{l}^{-1}}$and can also be expressed in $gmo{{l}^{-1}}$.
Molar mass of ${{H}_{2}}O$can be calculated by adding up the mass of components present in it as we know that ${{H}_{2}}O$consists of one molecule of oxygen and two molecules of hydrogen.
As we know that molecular weight of H = 1
Molecular mass of O = 16
Therefore, molecular mass of ${{H}_{2}}O$= $1\times 2+16=18$

Thus, molar mass of ${{H}_{2}}O$ is 18 $ gmo{{l}^{-1}}$.

Note: The molecular weight is synonym of molar mass particularly for molecular compounds and the formula weight is also used as synonym of molar mass it is frequently used for non-molecular compounds for example in ionic salts.