17.4 % (w/v) solution at 27 C is isotonic to 5.85 % (w/V) NaCl solution at 27 C. lf NaCl is 100 % ionised, the % ionisation of in aqueous solution is-
[At wt. of K = 39, Na = 23] :-
1. 25 %
2. 75 %
3. 50 %
4. None of the above
1. Benzene + Toluene
2. Acetone + Chloroform
3. Chloroethane + Bromoethane
4. Ethanol + Acetone
The freezing point of depression constant (Kf ) 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 up to 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:
Assertion (A): | C2H5I and C2H5Br form an ideal solution. |
Reason (R): | The interaction between the components are similar to those in the pure components. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
The latent heat of vaporization of water is 540 cal g-1 at 100 oC. Kb for water is:
1.
2.
3.
4.
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-
(Kf = 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 Kb 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 in grams that is required to obtain 250 ml of a semi-molar solution is -
1. | 17.75 g | 2. | 17.00 g |
3. | 15.75 g | 4. | 15.00 g |