6.02 x 10^21' molecules of urea are present in 100 'mL' of its solution. "The concentration of urea solution is -

Options

A. 0.02M
B. 0.01M
C. 0.001M
D. 0.1M

Answer

B

Explanation

Given number of molecules of urea `=6.02 xx 10^(20)`
`therefore` Number of moles `=(6.02 xx 10^(30))/(6.02 xx 10^(23)) = 1xx 10^(-3)` mol
Volume of the solution =100mL `=(100)/(1000) L= 0.1L`
Concentration of urea solution (in mol `L^(-1)`)
`=(1xx 10^(-3))/(0.1) = 1xx 10^(-2) mol L^(-1)=0.01` mol/L or M