A 500 g toothpaste sample has 0.4 g fluoride concentration. The fluoride concentration in terms of ppm will be -
1. | 200 ppm | 2. | 400 ppm |
3. | 500 ppm | 4. | 800 ppm |
The correct statement regarding a solution of two components A and B exhibiting positive deviation from ideal behaviour is :
1. | Intermolecular attractive force between A-A and B-B are stronger than those between A-B |
2. | ∆mixH = 0 at constant T and P |
3. | ∆mixV = 0 at constant T and P |
4. | Intermolecular attractive forces between A-A and B-B are equal to those between A-B |
A pair of isotonic solutions, among the following, is (assuming temperature to be the same) :
1. 0.1 (M) urea and 0.1 (M) NaCl
2. 0.1 (M) urea and 0.2 (M) MgCl2
3. 0.1 (M) NaCl and 0.1 (M) Na2SO4
4. 0.1 (M) Ca(NO3)2 and 0.1 (M) Na2SO4
The boiling point of an azeotropic mixture of water and ethanol is less than that of water and ethanol individually. The mixture shows:
1. No deviation from Raoult's law
2. Positive deviation from Raoult's law
3. Negative deviation from Raoult's law
4. That the solution is unsaturated
The mixture among the following that forms maximum boiling azeotrope is:
1. | Heptane + Octane | 2. | Water + Nitric acid |
3. | Ethanol + Water | 4. | Acetone + Carbon disulphide |
1.00 g of non-electrolyte solute (molar mass 250 g mol-1) was dissolved in 51.2 g of benzene. If the freezing point depression constant, Kf of benzene is 5.12 mol-1 kg K, the freezing point of benzene will be lowered by:
1. 0.4 K
2. 0.3 K
3. 0.5 K
4. 0.2 K
A solution containing 10 g/dm3 of urea (molecular mass = 60 g mol-1) is isotonic with a 5 % solution of a non-volatile solute. The molecular mass of this non-volatile solute is:
1. | 25 g mol-1 | 2. | 300 g mol-1 |
3. | 350 g mol-1 | 4. | 200 g mol-1 |
An aqueous solution is 1.00 molal in KI. The vapour pressure of the solution can be increased by:
1. Addition of NaCl
2. Addition of Na2SO4
3. Addition of 1.00 molal Kl
4. Addition of water
Consider the following statements about the composition of the vapour over an ideal 1:1 molar mixture of benzene and toluene. The correct statement is:
Assume that the temperature is constant at 25 oC.
(Given, vapour pressure data at 25 °C, benzene = 12.8 kPa, toluene = 3.85 kPa)
1. | The vapour will contain a higher percentage of toluene. |
2. | The vapour will contain equal amounts of benzene and toluene. |
3. | Not enough information is given to make a prediction. |
4. | The vapour will contain a higher percentage of benzene. |