Question

6.02 × 10^20 molecules of urea are present in 100ml solution the concentration of urea is

Answer 1

6.02×10^20 /6.02×10^23= no. of moles present in 100 ml solution=10^-3. 1 molar concentration means 1 mole of solute in 1 litre solution . hence in100 ml if 10^-3 moles are present then in 1litre solution 10^-2 moles are present so concentration of urea in solution is 0.01 M .

Answer 2

1 mole contains 6.02×10^23 molecules of urea
6.02×10^20 contains 1/6.02×10^23×6.02×10^20
=10^-3mole
concentration=mole/volume
=10^-3×1000/100
=1/100
=0.01