Some Basic Concepts of Chemistry - Result Question 24
####23. The weight of one molecule of a compound $C _{60} H _{122}$ is
[1995]
(a) $1.2 \times 10^{-20}$ gram
(c) $5.025 \times 10^{23}$ gram
(b) $1.4 \times 10^{-21}$ gram
(d) $6.023 \times 10^{23}$ gram
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Solution:
- (b) Molecular weight of $C _{60} H _{122}$ $=(12 \times 60)+122=842$.
Therefore, weight of one molecule
$ \begin{aligned} & =\frac{\text{ Molecular weight of } C _{60} H _{122}}{\text{ Avogadro’s number }} \\ & =\frac{842}{6.023 \times 10^{23}}=1.36 \times 10^{-21} g \simeq 1.4 \times 10^{-21} g \end{aligned} $
