# The weight of molecule of the compound ${C_{60}}{H_{122}}$ is:A) $1.4 \times {10^{ - 21}}g$B) $1.09 \times {10^{ - 21}}g$C) $5.025 \times {10^{23}}g$D) $16.023 \times {10^{23}}g$

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Hint: Molecular weight which is also known molecular mass and a mass of a molecule of a substance is based on atomic weight, as the atomic weight of carbon is 12 and hydrogen is 1, It is calculated in practice by taking the sum of atomic weights of the atoms making up the substance molecular formula.

Molecular weight is a measurement of the sum of the atomic weight or mass values of the atoms in a molecule.The calculation for molecular weight is based primarily on the molecular formula of a compound with reference to the periodic table (i.e., not the simplest formula, which most effective consists of the ratio of kinds of atoms and not the number). The number of every form of atom is multiplied by its atomic weight or mass after which is introduced to the weights of the alternative atoms.
For example, we find that hydrogen has an atomic weight of 1, and oxygen has atomic weight of 16. In order to calculate the molecular weight of single water molecule, we sum the contributions from each atom in single molecule that is,
${H_2}O = 2 \times 1 + 1 \times 16$
We get molecular weight as 18.
Molecular mass of given compound can be calculated as,
${C_{60}}{H_{122}} = C \times 60 + H \times 122$
${C_{60}}{H_{122}} = 12 \times 60 + 1 \times 122$
${C_{60}}{H_{122}} = 842g$
Hence, the weight of one mole is 842g.
So, we know total weight of $6.023 \times {10^{23}}$
Now weight of one molecule is, $= \dfrac{{842}}{{6.023 \times {{10}^{23}}}} = 139.797 \times {10^{ - 23}}$
i.e, $\approx 1.4 \times {10^{ - 21}}g$

Therefore the correct answer is option A.

Note: Molecular weight is utilized in chemistry to determine stoichiometry in various chemical reactions and their equations. Molecular weight is generally abbreviated by M.W. Molecular weight is either unit less or written in terms of atomic mass per unit or Daltons.