NEET Solved Paper 2014 Question 38
Question: In the Kjeldahl’s method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralised 10 mL of 1 M $ H _2SO _4 $ . The percentage of nitrogen in the soil is [AIPMT 2014]
Options:
A) 37.33
B) 45.33
C) 35.33
D) 43.33
Show Answer
Answer:
Correct Answer: A
Solution:
In Kjeldahl’s method, percentage of N is given by
% $ N=\frac{1\text{.4 }\times\text{ Normality},of,\text{acid }\times\text{ volume},ofacid}{Weight,of,compound} $ $ 1MH _2SO _4=2NH _2SO _4 $
$ \therefore $ %$ N=\frac{1.4\times 2\times 1}{0.75}=37.33 $%
