Question

Which one of the following contains the largest number of molecules?

• A. 8 g of methane
• B. $16800c{m}^3$ or carbon dioxide at STP
• C. 14 g of nitrogen
• D. 4 g of oxygen
• E. 64 g of sulphur dioxide

Answer 1

Answer: (E)

Number of moles $\frac{\text{wt}\text{.}\text{of}\text{substance}\text{in}\text{grams}}{\text{gram}\text{molecular}\text{wt}\text{.}}$ With the help of above formula we calculate number of moles for all the cases. It comes highest for 64 g of
$S{O}_2$ as, Mol. wt. of $S{O}_2=32+32=64g$
Gram mol. wt. = 64 g
$\therefore$ 64 g or 1 mol of $S{O}_2$ contains $=6.023\times {10}^{23}$ molecules