Question

$6.022\times {10}^{20}$ molecules of urea are present in $100ml$ of its solution. The concentration of urea solution is_________.

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

Answer 1

The correct option is B $0.01$ M

Given

6.02*${10}^{20}$ molecules of urea

volume of solution is 100/1000=0.1 L

Solution

1 mole of urea have 6.02*${10}^{23}$ molecules

no.of moles present=6.02*${10}^{20}$/6.02*${10}^{23}$=${10}^{-3}$

Concentration of Urea will be

${10}^{-3}$/0.1=0.01M

The correct option is B