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 :

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

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 - 

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

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

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 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. $5.12 \mathrm{K }{m}^{-1}$

If the relative decrease in vapour pressure is 0.4 for a solution containing 1 mol NaCl in 3 mol of ${\mathrm{H}}_2\mathrm{O}$, then percentage ionisation of NaCl will be -

1. 60%

2. 80%

3. 40%

4. 100%