Boiling of dil. HCl acid does not increase its concentration beyond 22.2 per cent because hydrochloric acid:
(1) is very volatile
(2) is extremely soluble in water
(3) forms a constant boiling mixture
(4) forms a saturated solution at this concentration
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 |
If the relative decrease in vapour pressure is 0.4 for a solution containing 1 mol NaCl in 3 mol of , then percentage ionisation of NaCl will be -
1. 60%
2. 80%
3. 40%
4. 100%
The Henry's law constant for the solubility of N2 gas in water at 298 K is 1.0 × 105 atm. The mole fraction of N2 in air is 0.8. The number of moles of N2 formed from air dissolved in 10 moles of water at 298 K and 5 atm pressure is-
1. | 4.0 × 10–4 mol | 2. | 4.0 × 10–5 mol |
3. | 5.0 × 10–4 mol | 4. | 4.0 × 10–6 mol |
freezes at 5.5C. At what temperature will a solution of 10.44 g of in 200 g of freeze ? Kf () = 5.12C/m
1. 4.60C
2. 0.89C
3. 5.50C
4. None of the above
Which of the following mixtures forms the maximum boiling azeotrope?
1. | Heptane + Octane | 2. | Water + Nitric acid |
3. | Ethanol + Water | 4. | Acetone + Carbon disulphide |
During osmosis, the flow of water through a semi-permeable membrane is:
1. | From a solution having higher concentration only. |
2. | From both sides of the semi-permeable membrane with equal flow rates. |
3. | From both sides of the semi-permeable membrane with unequal flow rates. |
4. | From a solution having lower concentration only. |
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 |
The freezing point depression constant for water is 1.86 oC m-1. If 5.00 g Na2SO4 is dissolved in 45.0 g H2O, the freezing point is changed by -3.82 oC. The Van’t Hoff factor for Na2SO4 is:
1. | 2.63 | 2. | 3.11 |
3. | 0.381 | 4. | 2.05 |