$6.02\times {10}^{20}$molecules of urea are present in 100 mL of its solution. The concentration of solution is

6.02 x 10²³ molecules = 1 mole
6.02 x 10²⁰ molecules = ?
No. of moles of urea $=\frac{6.02\times {10}^{20}}{6.02\times {10}^{23}}$
=10^-3 moles
Molarity $=\frac{\mathrm{n}\times 1000}{\mathrm{v}\left(\mathrm{ml}\right)}$
$=\frac{{10}^{-3}\times 1000}{100}={10}^{-2}\mathrm{M}$