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. ` 0.555m `
B. ` 5.55xx10^(-4)m `
C. ` 33.3m `
D. ` 3.33xx10^(-2)m `

Answer

B

Explanation

Molality `= ("Mass of methyl alcohol")/("Mass of solution")xx100`
Moles of urea `= (0.010)/(60) mol `
water at STP `(d=1 g//cm^(3) = 1 kg//dm^(3))=0.3 dm^(3) `
`=0.3kg`
`:.` Molality `= (0.010)/(60xx0.3)=5.55xx10^(-4) m `