Question

Calculate the molar mass of urea [CO(NH2)2]

Answer 1

Molar mass of Urea:

Urea --- Chemical formula -----[CO(NH2)2]

First let us calculate the molecular mass of Urea :

Atomic mass of C=12
Atomic mass of O=16
Atomic mass of N=14
Atomic mass of H=1

Molecular mass = sum of all the atomic masses of atoms.
=12+16+2[14+2x1]
12+16+32
=60u

∴Molar mass oF Urea -----60g

Answer 2

Molar mass of urea is $60 \frac {\text g}{\text mol}$

Solution:

The mass of a substance in grams which is present in 1 mole of substance is called molar mass.

Let’s write each every atom molar mass in Urea.

$Urea \quad molecular \quad formula = \left[ \mathrm { CO } \left( \mathrm { NH } _ { 2 } \right) _ { 2 } \right]$

$Molar \quad mass \quad of \quad Carbon = 12 \frac {\text g}{\text mol}$

$Molar \quad mass \quad of \quad Oxygen = 16 \frac {\text g}{\text mol}$

$Molar \quad mass \quad of \quad Nitrogen = 14 \frac {\text g}{\text mol}$

$Molar \quad mass \quad of \quad hydrogen = 1 \frac {\text g}{\text mol}$

$\left[ \mathrm { CO } \left( \mathrm { NH } _ { 2 } \right) _ { 2 } \right]=[ 12+16+(14+2(1))2$

$=12+16+2\times 16$

$\left[ \mathrm { CO } \left( \mathrm { NH } _ { 2 } \right) _ { 2 } \right]=60 \frac {\text g}{\text mol}$