Question

Find the nitrogen content of 100 kg of urea sample containing 96.43% pure urea.

Answer 1

Answer:

find nitrogen content of 100 kg urea sample contaning 96.43% pure urea

Answer 2

The sample contains 45 kg of nitrogen.

Explanation:

• The formula of urea is $NH_2CONH_2$

• The molecular weight of urea $= 14+ (1\times2)+ 12+ 16 +14+ (1\times2) = 14 +2 + 28+ 14 +2 =60gmol^{-1}$

Since, two atoms of N are there in one molecule of urea

Therefore, in a 60 g sample of urea = 28 g of N would be present

Using unitary method:

• In 1 g sample of urea $= \frac{28}{60} g$ of Nitrogen (N) would be present

• In 100 kg sample of urea $= \frac{28}{60}\times 100 kg$ of N would be present.

However, the sample is 96.43 % pure.

Hence, in the given 100 kg sample, only 96.43 kg of urea would be present.

• In the given 100 kg sample of urea

$= \frac{28}{60}\times 96.43 kg$ of N would be present.

$= 45 kg$ of N would be present.