Question

Assertion :Vapour density of $C{H}_4$ is half of $O_2$. Reason: 1.6 g of $C{H}_4$ contains same number of electrons as 3.2 g of $O_2$.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

We know that,

Vapour density $=\frac{Molarmass}{2}$

$d_{C{H}_4}=\frac{16}{2}=8$

$d_{O_2}=\frac{32}{2}=16$

So,

$d_{C{H}_4}=\frac{1}{2}\times d_{O_2}$ (Assertion correct)

No. of electrons in $1.6gC{H}_4=10\times \frac{1.6}{16}\times N_A=N_A$

No. of electrons in $3.2g{O}_2=16\times \frac{3.2}{32}\times N_A=1.6N_A$ (Reason wrong)