Question

If $1$ gram of Sulphur dioxide contains x molecules, how many molecules will be present in $1$ gram of oxygen? (S = $32$ u ; O = $16$u)

Answer 1

$1$ mole of $S{O}_2=64g$ of $S{O}_2=6.022\times {10}^{23}$ molecules of $S{O}_2$

$1g$ of $S{O}_2=\frac{6.022\times {10}^{23}}{64}=x$ molecules of $S{O}_2$ (given)

Now, $32g$ of $O_2=6.023\times {10}^{23}$ molecules of $O_2$

$\therefore 1g$ of $O_2=\frac{6.023\times {10}^{23}}{32}$ molecules of $O_2$

$=\left(\frac{6.023\times {10}^{23}}{64}\right)\times 2$ molecules of $O_2$

$=\frac{x}{2}$ molecules of $O_2$