Question

Calculate the molar mass of ${{S}_{8}}$ .

Answer 1

Hint: Molar mass of a chemical compound is calculated by the ratio of mass of the substance in grams to the number of moles of a substance. Molar mass is generally calculated in grams.

Complete Solution :
Since in this question the number of moles of sulphur is not given this means that we cannot calculate molar mass of sulphur using the above formulae.
Now we know that,
Atomic number of sulphur = 16
Atomic mass of sulphur = 32 g
Molar mass of sulphur = $8\times 32 = 256 g$
Hence, the molar mass of sulphur i.e. ${{S}_{8}}$ is 256 g

Additional information-To calculate the number of atoms first we have to calculate the number of moles of the given element as the number of moles is already given, then the number of atoms will be equal to the product of number of moles and Avogadro’s number. A mole is generally used as a unit for the number of atoms or molecules or particles of a material.

Note: 1 mole = $6.022 \times {{10}^{23}}$ particle or atoms or molecules or electrons or protons etc. The number of the constituent particles of atoms such as molecules or atoms or ions present in a given sample is related with the mass of the substance present in the sample using Avogadro's number. The SI unit of Avogadro’s number is the inverse of mole.
- Avogadro’s number is dimensionless. It also helps to relate the molar volume of a substance to the average volume which is occupied by one of the particles.