Question

Ammonia gas diffuses twice as fast as does
gas X. The gas X'is
1) So, 2) C,Ho 3) C,H, 4) C,​

Answer 1

Answer: C) C5H8.

Explanation:

According to the Graham's Law of Diffusion,

Rate is inversely proportional to the square root of the molecular mass of the compound

So,

R1/R2 = √M2/M1

Thus, the rate of NH3 to be double the molecular mass of the compound X should be 4 times the molar mass of Ammonia.

Molar mass of NH3 = 17

Thus, Molar mass of Gas X should be 17*4 = 68.

And we know that the molar mass of C5H8 is 68 ( 5*Mass of carbon + 8* Hydrogen = 5*12+8*1 = 68)

Hence, the answer should be C) C5H8.

Answer 2

Answer:

The correct answer is option C

Explanation:

Let molecular weight of a gas be $x$

$\begin{aligned}&\mathrm{r}_{\mathrm{NH}_{3}}=2 \mathrm{r}_{\mathrm{x}} ; \mathrm{M}_{\mathrm{NH}_{3}}=17 \\&\therefore \frac{\mathrm{r}_{\mathrm{NH}_{3}}}{\mathrm{r}_{\mathrm{X}}}=2=\sqrt{\frac{\mathrm{M}_{\mathrm{X}}}{\mathrm{M}_{\mathrm{NH}_{3}}}} \\&2=\sqrt{\frac{\mathrm{M}_{\mathrm{x}}}{17}}\end{aligned}$

Squaring on both sides

$\begin{aligned}&4=\frac{M_{x}}{17} \\&M_{x}=17 \times 4 \\&M_{x}=68\end{aligned}$

$\therefore$ Molecular weight of gas $x$ is 68 .

And we know that the molar mass of C5H8 is 68 ( 5*Mass of carbon + 8* Hydrogen = 5*12+8*1 = 68)

Hence, the answer should be C) C5H8.