Organic Chemistry Some Basic Principles And Techniques Ques 46
46. In the Kjeldahl’s method for estimation of nitrogen present in a soil sample, ammonia evolved from $0.75$ $ g$ of sample neutralized $10 $ $mL$ of $1 M$ $ H_2 SO_4$. The percentage of nitrogen in the soil is :
[2014]
(a) $37.33$
(b) $45.33$
(c) $35.33$
(d) $43.33$
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Answer:
Correct Answer: 46.(a)
Solution:
- (a) $10 $ $mL, 1 M $ $H_2 SO_4=20 $ $mL, 1 M $ $NH_3$
$\because \quad$ wt of $N$ in one mole $NH_3=14$
$\therefore 20 \times 10^{-3} mol $ $NH_3 \longrightarrow$ $ 20 \times 10^{-3} \times 14 \text{ nitrogen } $
$\therefore \quad 0.75$ $ g$ of sample contains
$ =\frac{14 \times 20 \times 10^{-3}}{0.75} \times 100=37.33 \% $
BETA
