Question

$1$ g of oxygen combines with $0.1260$ g of hydrogen to form $H_{2}O$. $1$ g of nitrogen combines with $0.2160$ g of hydrogen to form $N{H}_3$. If $x$ g weight of oxygen is required to combine with $1$ g of nitrogen to for monoxide, then find the value of $100x$.

• A. $171$
• B. $150$
• C. $200$
• D. None of the above

Answer 1

The correct option is A $171$

In $H_{2}O$, $0.126$ g of $H_2$ combines with $1$ g of oxygen.
$\therefore 1$ g of $H_2$ combines with $\frac{1}{0.126}=7.936$ g of $O_2$
In $N{H}_3$, $0.216$ g of $H_2$ combines with $1$ g of $N_2$.
$\therefore 1$ g of $H_2$ combines with $\frac{1}{0.216}=4.629$ g of $N_2$
Ratio of $O:N$ in $H_{2}O$ and $N{H}_3$ which combines with a fixed weight of $H_2\left(1g\right)=$ $7.936:4.629$ $=\frac{7.936}{4.629}:\frac{4.629}{4.629}=1.71:1$
Weight of oxygen which combines with $1$ g of $N$ should be $1.71=x$ g or its simple multiple.

Hence, the value of $100x$ is $171$.