Advertisements
Advertisements
प्रश्न
Calculate the freezing point of a solution containing 60 g of glucose (Molar mass = 180 g mol–1) in 250 g of water. (Kf of water = 1.86 K kg mol–1)
Advertisements
उत्तर
Given,
W2 = 60 g
M2 = 180 g mol-1
W1 = 250 g
Kf = 1.86 K kg mol–1
ΔTf = kfm
`T_f^0 - T_f = (K_f xx w_2 xx 1000)/M_2xxw_1`
`2.73 - T_f = (1.86 xx 60 xx 1000)/(180xx250)`
`2.73 - T_f = (1.86 xx 60 xx 1000)/(180 xx 250)`
273.15 - Tf = 2.48
Tf = 273.15 - 2.48 = 270.67 K
Hence, the freezing point of water is 270.67 K or -2.48°C
APPEARS IN
संबंधित प्रश्न
Calculate the freezing point of the solution when 31 g of ethylene glycol (C2H6O2) is dissolved in 500 g of water.
(Kf for water = 1.86 K kg mol–1)
A 5% solution (by mass) of cane sugar in water has freezing point of 271 K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 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 molar depression constant for benzene is 5.1 K kg mol−1. Calculate the atomic masses of A and B.
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
A 5% solution (by mass) of cane sugar in water has a freezing point of 271 K and a freezing point of pure water is 273.15 K. The freezing point of a 5% solution (by mass) of glucose in water is:
The freezing point of equimolal aqueous solution will be highest for ____________.
Which of the following 0.10 m aqueous solutions will have the lowest freezing point?
1.2 mL of acetic acid is dissolved in water to make 2.0 L of solution. The depression in freezing point observed for this strength of acid is 0.0198° C. The percentage of dissociation of the acid is ______. [Nearest integer]
[Given: Density of acetic acid is 1.02 g mL–1, Molar mass of acetic acid is 60 g/mol.]
Kf(H2O) = 1.85 K kg mol–1
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
