Some Basic Concepts of Chemistry - Result Question 13
17. The ratio mass of oxygen and nitrogen of a particular gaseous mixture is $1: 4$. The ratio of number of their molecule is
(2014 Main)
(a) $1: 4$
(b) $7: 32$
(c) $1: 8$
(d) $3: 16$
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Answer:
Correct Answer: 17. (b)
Solution:
- $\dfrac{n_{\mathrm{O}2}}{n{\mathrm{N}2}}=\dfrac{\dfrac{\left(m{\mathrm{O}2}\right)}{\left(M{\mathrm{O}2}\right)}}{\dfrac{\left(m{\mathrm{N}2}\right)}{\left(M{\mathrm{N}_2}\right)}}$
where, $m_{\mathrm{O}_2}=$ given mass of $\mathrm{O}2, m{\mathrm{N}_2}=$ given mass of $\mathrm{N}_2$,
$M_{\mathrm{O}_2}=$ molecular mass of $\mathrm{O}2, M{\mathrm{N}_2}=$ molecular mass of $\mathrm{N}_2$,
$n_{\mathrm{O}_2}=$ number of moles of $\mathrm{O}2, n{\mathrm{N}_2}=$ number of moles of $\mathrm{N}_2$
$=\left[\frac{m_{\mathrm{O}2}}{m{\mathrm{N}_2}}\right] \frac{28}{32}=\frac{1}{4} \times \frac{28}{32}=\frac{7}{32}$
BETA
