Chemistry - Mole Concept Question with Solution | TestHub

Molar mass of hydrocarbon can be determtextnd with the help of ideal gas equation:

$\text{P}\text{V}=\text{n}\text{R}\text{T}$

$\text{P}\text{V}=\frac{\text{w}}{\text{M}}\text{R}\text{T}$

$1\times \frac{22.4}{1000}\text{L}=\frac{0.078}{\text{M}}\times 0.082\times 273\text{k}$

$\text{m}=78\text{g}$

$\text{M}\text{o}\text{l}\text{e}\text{c}\text{u}\text{l}\text{a}\text{r}\text{f}\text{o}\text{r}\text{m}\text{u}\text{l}\text{a}=\text{n}\times \left(\text{E}\text{m}\text{p}\text{e}\text{r}\text{i}\text{a}\text{l}\text{f}\text{o}\text{r}\text{m}\text{u}\text{l}\text{a}\right)$

$\text{n}=\frac{\text{m}\text{o}\text{l}\text{e}\text{c}\text{u}\text{l}\text{a}\text{r}\text{f}\text{o}\text{r}\text{m}\text{u}\text{l}\text{a}}{\text{e}\text{m}\text{p}\text{i}\text{r}\text{i}\text{a}\text{l}\text{m}\text{a}\text{s}\text{s}}$

$\text{E}\text{m}\text{p}\text{i}\text{r}\text{i}\text{a}\text{l}\text{m}\text{a}\text{s}\text{s}=\text{C}\text{H}$

So, Empirical mass$\text{=12}\text{H=13}$

$\therefore \text{n}=\frac{78}{13}=6$

$\text{M}\text{o}\text{l}\text{e}\text{c}\text{u}\text{l}\text{a}\text{r}\text{f}\text{o}\text{r}\text{m}\text{u}\text{l}\text{a}={\left(\text{C}\text{H}\right)}_6={\text{C}}_6{\text{H}}_6$