Question

The freezing point of one molal `NaCl`solution assuming `NaCl`to be `100%`dissociated in water is (molal depression constant=`1.86)`
A. `-1.86^(@)C`
B. `-3.72^(@)C`
C. `+1.8^(@)C`
D. `+3.72^(@)C`

Answer 1

Correct Answer - B
For `NaCl i=2`
`DeltaT_(f)=2K_(f)m=2xx1.86xx1=3.72`
`T_(s)=T=DeltaT_(f)=0.3.72=-72^(@)C`