Question

Rank the following aqeuous solutions in order of decreasing boiling point and in order of decreasing vapour pressure at 298 K.

i) 0.03 m sucrose

ii) 0.01 m silver nitrate

iii) 0.02 m calcium chloride

Answer 1

iii) 0.02 m calcium chloride   < ii) 0.01 m silver nitrate   < i) 0.03 m sucrose

order of decreasing boiling point.

CaCl2   gives   3 ions in the solution. so it hve higher boiling point then remaining.   AgNO3 gives two ions in the solution. Sucrose do not dissociate.

as number of particles more more will be increasing in boiling point and lesser the vapour pressure.

iii) 0.02 m calcium chloride   < ii) 0.01 m silver nitrate   < i) 0.03 m sucrose

order of increasing vapour pressure.