Question

Calculate the molar mass of ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{6}}}$.

Answer 1

Hint : Molar mass of hydrogen is $1{\text{ g}}$ and that of carbon is $12{\text{ g}}$. Using this information, we can calculate the molar mass of any compound which is made up of carbon and hydrogen.

Complete Step By Step Answer:
The mass of one mole of a species in grams is known as molar mass.
We know that the molar mass of the carbon atom is $12{\text{ g}}$and that of hydrogen is $1{\text{ g}}$.
In a molecule of ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{6}}}$, there are two atoms of carbon and six atoms of hydrogen.
Therefore, molar mass of ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{6}}} = (2 \times 12){\text{ g}} + (6 \times 1){\text{ g}}$
$= 24{\text{ g}} + 6{\text{ g}} = 30{\text{ g}}$
Hence, the molar mass of ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{6}}}$is $30{\text{ g}}$.

Additional Information:
A mole (mol) is the unit of measurement for the amount of substance in the International System of Units (SI). It is defined as exactly $6.02214076 \times {10^{23}}$ particles, which may be atoms, molecules, ions, or electrons. This number is known as Avogadro number and chosen so that the mass of one mole of a chemical compound in grams is numerically equal, for most practical purposes.
The definition was adopted in November 2018 as one of the seven SI base units, revising the previous definition that specified one mole as the amount of substance in $12$ grams of $^{{\text{12}}}{\text{C}}$, an isotope of carbon.
The dalton or unified atomic mass unit (symbols: ${\text{Da}}$or ${\text{u}}$) is a unit of mass. It is defined as one twelfth of the mass of an unbound neutral atom of $^{{\text{12}}}{\text{C}}$ in its nuclear and electronic ground state and at rest.

Note :
If any specific information about isotope is not given then the most abundant isotope is to be considered. The most abundant isotope of carbon is $^{{\text{12}}}{\text{C}}$ and that of hydrogen is $^{\text{1}}{\text{H}}$.