Question

The numbers of atoms present in $11.2L$ of $S{O}_2$ at STP is: (Where $N_A$ is the Avogadro constant)

• A. $1.5\times N_A$
• B. $2N_A$
• C. $N_A$
• D. $4N_A$

Answer 1

Answer: (A)

$1.5\times N_A$

$1$ $mole$ of any gas at STP has volume $=22.4$ $L$

Here, volume $=11.2$ $L$

$⟹1$ $mole=22.4$ $L$

$⟹\frac{1}{22.4}=1$ $L$

$⟹11.2$ $L=\frac{11.2}{22.4}=0.5$ $moles$

One molecule of $S{O}_2$ is made up of 3 atoms.

$\therefore$ No.of atoms $=3\times 0.5\times N_A=1.5\times N_A$