Question

calculate the mass of nitrogen in 5kg urea

Answer 1

The formula for urea is (NH2)2CO. The molar mass for urea is 14*2+1*4+12+16= 60 g/mole. In this 60 g of urea, nitrogen has a mas of 28 g. So by simple proportion in 5 kg of urea, nitrogen has a mass = 5 kg*28 g/60 g = 2.3 kg.

Answer 2

First of all, calculate the mass of compound urea:-

You get : 60 g

then,

60g urea mass is 5 kg

So,

Mass of nitrogen in compound =>N2=>14*2=28

28 g mass of nitrogen :-

5/60*28=2.33 kg