Question

Identify the true statements among the following.
(A) 4 g of helium and 2 g of hydrogen contain the same number of molecules.
(B) If 1.1 g of a gas occupied a 560 m$l$ of volume, its vapour density is 22.
(C) Both 1 mole of sulphuric acid 1 mole of ammonium hydroxide contains the same number of hydrogen atoms.
(D) 48 g of oxygen and ozone occupy same volume under similar conditions.

• A. (B) and (C)
• B. (A) and (B)
• C. (B) and (D)
• D. (A) and (D)

Answer 1

The correct option is B (A) and (B)

A. $4g$ of $He$ and $2g$ of hydrogen

Since, $1$ mole of any compound has $N_A$ number of molecules.

So, $4g$ of $He$ has $N_A$ molecules $\left(H{e}_2\right)$

$2g$ of $H_2$ has $N_A$ molecules $\left(H_2\right)$

B. Also, $1.1g$ of a gas occupies $560ml$ of volume.

So, since $vapordensity=\frac{densityofthegas}{densityof{H}_2}$

$Densityofgas=\frac{Massofgas}{Volumeofgas}=\frac{1.1}{560}\times 1000=1.96g/L$

$Densityof{H}_2=0.08988g/L$

$V.D=\frac{1.96}{0.089}=22$