Calculate the molality of NaCl solution whose elevation in boiling point is equal to the depression in freezing point of 0.25 m sodium carbonate solution in water assuming complete dissociation of salts. (`k_(f) = 1.86 K m^(-1) , k_(b) = 0.52 K m^(-1)`)

Answer

`1.34`m

Explanation

`NaCl to Na^(+) + Cl^(-) (i=2)`
`Na_(2)CO_(3)^(2-) (i=3)`
`Delta T_(b) (NaCl) = Delta T_(b) (Na_(2)CO_(3))`
` ixx K_(b) xx m = ixx k_(f) xx m`
` 2 xx 0.52 xx m = 3 xx 1.86 xx 0.25`
` m = 1.34` m