Question

$10$ mL sample of human urine was found to have $5$ mg of urea on analysis. Calculate the molarity of the given sample with respect to urea (molecular mass $=60$ g/mol).

• A. $0.008$
• B. $0.01$
• C. $0.002$
• D. None of the above

Answer 1

The correct option is A $0.008$

$\text{Molarity}=\frac{W_2\times 1000}{M{w}_2\times V_{sol}\left(\text{in mL}\right)}$ $⟹W_2=5$ mg $=5\times {10}^{-3}$ g
$\therefore M=\frac{5\times {10}^{-3}\times {10}^3}{60\times 10}=0.008$