Question

A flask of methane$\left(C{H}_4\right)$ was weighed. Methane was then pushed out and the flask again filled with oxygen at the same temperature and pressure. The mass of oxygen would be:

• A. the same as the methane
• B. half of the methane
• C. double of that of methane
• D. negligible in comparison to that

Answer 1

Answer: (C)

double of that of methane

According to Avogadro's Law ,

$n_1=n_2$

where $n=$ number of moles

We have, number of moles $n=\frac{weight}{moecularweight}$

$\frac{W_{O_2}}{W_{C{H}_4}}$ = $\frac{M_{O_2}}{M_{C{H}_4}}$

$\frac{W_{O_2}}{W_{C{H}_4}}$ = $\frac{32}{16}$

$\frac{W_{O_2}}{W_{C{H}_4}}$ = 2

Hence, Mass of oxygen would be double of that of methane.