Question

12 gram sample of gas occupies 19.2 litre at STP what is the average molecular weight of the gas

Answer 1

Answer:

15

Explanation:

Let us convert liter to cm^3. I liter = 1000 cm^3

So, 19.2 liter = 19.2 x 1000 = 19200 cm^3

We know molar volume ( Or you can say volume of 1 mol) = 24000cm^3       [ sometimes 24 dm^3]

Formula is Mole = $\frac{volume}{molar \\ volume}$

So, Mole = $\frac{19200}{24000}$ = 0.8 mol

Another formula is Mole = $\frac{Mass}{Mr\\}$  [ Mr stands for molecular formula or molecular weight].

Rearrange : Mr = $\frac{Mass}{Mole}$

So, Mr = $\frac{12}{0.8}$ = 15

Therefore, Molecular weight of the gas is 15