The molality of a urea solution in which ` 0.0100 g ` of urea, ` [(NH_(2))_(2)CO] ` is added to ` 0.3000 dm^(3) `of water at STP is

Options

A. `5.55 xx 10^(-4) m`
B. `33.3 m`
C. `3.33 xx 10^(-2) m`
D. `0.555 m`

Answer

A

Explanation

Density of water at `25^(@)C = 1 g//mL`
Volume of water `= 0.3xx 1000 = 300 mL`
Mass of water ` = 300 xx 1 = 300g`
Moles of urea `= (0.01)/(60)`
Molality ` = (0.01 xx 1000)/(60 xx 300) = 5.555 xx 10^(-4) m`.