Question

An organic compound of mass 0.3g gave 50ml nitrogen at ${27}^0$C and 715mm pressure. The % of nitrogen in the compound is:

• A. 17.83
• B. 50
• C. 25
• D. 20

Answer 1

Answer: (A)

17.83

$P_1=715mm$
$V_1=50ml$
$T_1=27c=300k$
$P_2=760mm$
at STP
$V_2=?$
$T_2=273k$
$\frac{P_1{V}_1}{T_1}=\frac{P_2{V}_2}{T_2}$
$V_2=\frac{P_1{V}_1}{T_1}\times \frac{T_2}{P_2}=\frac{715\times 50}{300}\times \frac{273}{760}$
$\therefore V_2=42.80ml.$
%$N_2=\frac{28}{22400}\times \frac{v_2}{m}\times 100$
$=\frac{28}{22400}\times \frac{42.80}{0.3}\times 100$
%$N_2=17.83$%