17.4 % (w/v) ${\mathrm{K}}_2{\mathrm{SO}}_4$ solution at 27 $°$C is isotonic to 5.85 % (w/V) NaCl solution at 27 $°$C. lf NaCl is 100 % ionised, the % ionisation of ${\mathrm{K}}_2{\mathrm{SO}}_4$ in aqueous solution is-

[At wt. of K = 39, Na = 23] :-

1. 25 %

2. 75 %

3. 50 %

4. None of the above

The mixture that shows positive deviation from Raoult's law is-

1. Benzene + Toluene

2. Acetone + Chloroform

3. Chloroethane + Bromoethane

4. Ethanol + Acetone

The freezing point of depression constant (K_f ) of benzene is 5.12 K kg mol^–1. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is-
(rounded off upto two decimal places):
1. 0.80 K
2. 0.40 K
3. 0.60 K
4. 0.20 K

The azeotropic mixture of water and ethanol boils at 78.15 ^oC. When this mixture is distilled, it is possible to obtain-

1. Pure H₂O

2. Pure C₂H₅OH

3. Pure H₂O as well as pure C₂HOH

4. Neither H₂O nor C₂H₅OH in their pure state 

Select the correct option based on statements below:

The latent heat of vaporization of water is 540 cal g^-1 at 100 ^oC. K_b for water is:

1. $0.562 \mathrm{K }{m}^{-1}$

2. $1.86 \mathrm{K }{m}^{-1}$

3. $0.515 \mathrm{K }{m}^{-1}$

4. $5.12 \mathrm{K }{m}^{-1}$

The Van't Hoff factor for 0.1 M Ba(NO₃)₂ solution is 2.74. The degree of dissociation is -

1. 91.3 %

2. 87 %

3. 100 %

4. 74 %

The molality of a solution containing a certain solute, if there is a freezing point depression of 0.184 °C, is-

(K_f = 18.4)

1. 0.01 m

2. 10 m

3. 0.05 m

4. 100 m

A solution containing 3.3 g of a substance in 125 g of benzene (b.p. 80 °C) boils at 80.66 °C. If K_b for one litre of benzene is 3.28 °C m^-1, the molecular weight of the substance shall be -

1. 127.20 g mol^-1

2. 131.20 g mol^-1

3. 137.12 g mol^-1

4. 142.72 g mol^-1

Amount of oxalic acid $({\left(\mathrm{COOH}\right)}_2.2{\mathrm{H}}_2\mathrm{O})$ in grams that is required to obtain 250 ml of a semi-molar solution is -