A 5 % solution (by mass) of cane sugar in water has freezing point of 271 K. Freezing point of 5 % glucose in water would be: (freezing point of pure water is 273.15 K)
1. 279.24 K
2. –269.06 K
3. 275.42 oC
4. 269.06 K
Two elements A and B form compounds having formula AB2 and AB4. When dissolved in 20 g of benzene (C6H6), 1 g of AB2 lowers the freezing point by 2.3 K whereas 1.0 g of AB4 lowers it by 1.3 K. The atomic masses of A and B are respectively:
(Kf for benzene is 5.1 K kg mol-1)
1. 15.59 u and 52.64 u
2. 25.59 u and 42.64 u
3. 13.59 u and 52.64 u
4. 23.59 u and 32.64 u
The depression in the freezing point of water when 10 g of CH3CH2CHClCOOH is added to 250 g of water will be:
(Ka = 1.4 × 10–3, Kf = 1.86 K kg mol–1)
1. 0.32 K
2. 2.87 K
3. 0.65 K
4. 5.03 K