Question

The freezing point of `1` molal `NaCl` solution assuming `NaCl` to be `100%` dissociated in water is:
A. (a) `-1.86^(@)C`
B. (b) `-3.72^(@)C`
C. (c ) `+1.86^(@)C`
D. (d) `+3.72^(@)C`

Answer 1

Correct Answer - B
`Delta T_(f) = 1.86 xx 1 xx 2 = 3.72`,
`:. T_(f) = 0-3.72 = -3.72^(@)C`
`NaCl` dissociates to give experimental molality `= 1xx2=2`