Question

In Dumas method, $0.3g$ of an organic compound gave $45mL$ of nitrogen at STP. The percentage of nitrogen is

• A. 16.9
• B. 18.7
• C. 23.2
• D. 29.6

Answer 1

Answer: (B)

In Dumas method,

From the volume of $N_2$ at $STP$, the percentage of nitrogen is calculated as

$\%$ of nitrogen $=\frac{28V\times 100}{22400\times W}$

Here, $V=$ volume of $N_2$ evolved at STP

$W=$ weight of organic compound taken

$W=0.3g$

$V=45mL$

$\%$ Nitrogen $=\frac{V}{8W}$

$=\frac{45}{8\times 0.3}$

$=18.75$