The Ka of an acid is 3.2 x 10-5. The degree of dissociation of the acid at concentration of 0.2 M is
6.0 x 10-2
1.26 x 10-2
4.0 x 10-2
0.04 x 10-3
Addition of a non-volatile solute causes lowering in vapour pressure of a solvent from 0.8 atm to 0.2 atm. What is the
mole fraction of solvent?
0.25
0.75
0.50
Cannot be predicted
A.
0.25
From Raoult's law,
Hence, mole fraction of solvent = 1 - 0.75 =0.25
What would be the freezing point of aqueous solution containing 17g of C2H5OH in 1000 g of water?
0.34°C
0.0°C
-0.34°C
-0.69°C
The pH of a solution is 5.0. If H+ ion concentration is decreased 100 times. Then the solution will be :
neutral
more acidic
basic
of the same acidity
At a temperature, vapour pressure of pure benzene is 640 mm Hg. On dissolving 2.175 g of a non-volatile solid solute in 39.0 g benzene, vapour pressure of the solution if found to be 600 mm Hg. The molecular mass of solute is:
65.25
54.94
63.55
87.62
50 cm3 ethylene glycol is dissolved in 50 g water. Freezing point of solution is -34°C. Assuming ideal behaviour than density of ethylene glycol is (for water , Kf =1.86 K kg mol-1)
1.273 g/cm3
2.173 g/cm3
1.133 g /cm3
2.612 g/cm3
The average molar heat capacity at constant volume of gaseous mixture contained 2 moles of each of two ideal gases X (CV , m = R) and Y (CV , m = R)
2R
3R
4R
8R
How many grams of CaC2O4 will dissolve in distilled water to make one litre of saturated solution? Solubility product of CaC2O4 is 2.5 x 10-9 mol2 litre-2 and its molecular weight is 128
0.0640 gm
0.0032 gm
0.0128 gm
0.0064 gm
1 g of a non-volatile, non-electrolyte solute of molar mass 250 g/mol was dissolved in 51.2 g of benzene. If the freezing point depression constant , kf of benzene is 5.12 kg K mol-1 , the freezing point of benzene is lowered by :
0.3 K
0.5 K
0.2 K
0.4 K
A 6% solution of urea is isotonic with :
1M solution of glucose
0.05 M solution of glucose
6% solution of glucose
25% solution of glucose