Freezing point depression Tf = i x Kf x m
where i is van\'t Hoff factor, Kf is freezing point depression constant of water and m is molality
Kf of water = 1.86oC/m
1. 0.15 m Pb(CH3COO)2: Tf = 3 x 1.86 x 0.15 = 0.837oC
2. 0.17 m FeI2: Tf = 3 x 1.86 x 0.17 = 0.9486oC
3. 0.24 m KOH: Tf = 2 x 1.86 x 0.24 = 0.8928oC
4. 0.42 m Urea (nonelectrolyte): Tf = 1 x 1.86 x 0.42 = 0.7812oC
Since larger Tf gives lower freezing point:
1. 0.15 m Pb(CH3COO)2 ---- C. Third lowest freezing point
2. 0.17 m FeI2 ---- A. Lowest freezing point
3. 0.24 m KOH ---- B. Second lowest freezing point
4. 0.42 m Urea (nonelectrolyte) ---- D. Highest freezing point
Solution
Freezing point depression Tf = i x Kf x m
where i is van\'t Hoff factor, Kf is freezing point depression constant of water and m is molality
Kf of water = 1.86oC/m
1. 0.15 m Pb(CH3COO)2: Tf = 3 x 1.86 x 0.15 = 0.837oC
2. 0.17 m FeI2: Tf = 3 x 1.86 x 0.17 = 0.9486oC
3. 0.24 m KOH: Tf = 2 x 1.86 x 0.24 = 0.8928oC
4. 0.42 m Urea (nonelectrolyte): Tf = 1 x 1.86 x 0.42 = 0.7812oC
Since larger Tf gives lower freezing point:
1. 0.15 m Pb(CH3COO)2 ---- C. Third lowest freezing point
2. 0.17 m FeI2 ---- A. Lowest freezing point
3. 0.24 m KOH ---- B. Second lowest freezing point
4. 0.42 m Urea (nonelectrolyte) ---- D. Highest freezing point.
Freezing point depression Tf = i x Kf x mwhere i is vant Hoff fa.pdf
1. Freezing point depression Tf = i x Kf x m
where i is van't Hoff factor, Kf is freezing point depression constant of water and m is molality
Kf of water = 1.86oC/m
1. 0.15 m Pb(CH3COO)2: Tf = 3 x 1.86 x 0.15 = 0.837oC
2. 0.17 m FeI2: Tf = 3 x 1.86 x 0.17 = 0.9486oC
3. 0.24 m KOH: Tf = 2 x 1.86 x 0.24 = 0.8928oC
4. 0.42 m Urea (nonelectrolyte): Tf = 1 x 1.86 x 0.42 = 0.7812oC
Since larger Tf gives lower freezing point:
1. 0.15 m Pb(CH3COO)2 ---- C. Third lowest freezing point
2. 0.17 m FeI2 ---- A. Lowest freezing point
3. 0.24 m KOH ---- B. Second lowest freezing point
4. 0.42 m Urea (nonelectrolyte) ---- D. Highest freezing point
Solution
Freezing point depression Tf = i x Kf x m
where i is van't Hoff factor, Kf is freezing point depression constant of water and m is molality
Kf of water = 1.86oC/m
1. 0.15 m Pb(CH3COO)2: Tf = 3 x 1.86 x 0.15 = 0.837oC
2. 0.17 m FeI2: Tf = 3 x 1.86 x 0.17 = 0.9486oC
3. 0.24 m KOH: Tf = 2 x 1.86 x 0.24 = 0.8928oC
4. 0.42 m Urea (nonelectrolyte): Tf = 1 x 1.86 x 0.42 = 0.7812oC
Since larger Tf gives lower freezing point:
1. 0.15 m Pb(CH3COO)2 ---- C. Third lowest freezing point
2. 0.17 m FeI2 ---- A. Lowest freezing point
3. 0.24 m KOH ---- B. Second lowest freezing point
4. 0.42 m Urea (nonelectrolyte) ---- D. Highest freezing point
