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 :

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

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%

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-

${\mathrm{C}}_6{\mathrm{H}}_6$ freezes at 5.5$°$C. At what temperature will a solution of 10.44 g of ${\mathrm{C}}_4{\mathrm{H}}_{10}$ in 200 g of ${\mathrm{C}}_6{\mathrm{H}}_6$ freeze ? K_f (${\mathrm{C}}_6{\mathrm{H}}_6$) = 5.12$°$C/m

1. 4.60$°$C

2. 0.89$°$C

3. 5.50$°$C

4. None of the above

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

Which of the following mixtures forms the maximum boiling azeotrope?

During osmosis, the flow of water through a semi-permeable membrane is:

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: