1
JEE Main 2021 (Online) 17th March Morning Shift
Numerical
+4
-1
The oxygen dissolved in water exerts a partial pressure of 20 kPa in the vapour above water. The molar solubility of oxygen in water is __________ $$\times$$ 10$$-$$5 mol dm$$-$$3. (Round off to the Nearest Integer).

[Given : Henry's law constant = KH = 8.0 $$\times$$ 104 kPa for O2. Density of water with dissolved oxygen = 1.0 kg dm$$-$$3 ]
2
JEE Main 2021 (Online) 16th March Evening Shift
Numerical
+4
-1
At 363 K, the vapour pressure of A is 21 kPa and that of B is 18 kPa. One mole of A and 2 moles of B are mixed. Assuming that this solution is ideal, the vapour pressure of the mixture is ___________ kPa. (Round off to the Nearest Integer).
3
JEE Main 2021 (Online) 16th March Morning Shift
Numerical
+4
-1
AB2 is 10% dissociated in water to A2+ and B$$-$$. The boiling point of a 10.0 molal aqueous solution of AB2 is __________$$^\circ$$C. (Round off to the Nearest Integer).

[Given : Molal elevation constant of water Kb = 0.5 K kg mol$$-$$1 boiling point of pure water = 100$$^\circ$$C]
4
JEE Main 2021 (Online) 26th February Evening Shift
Numerical
+4
-1
When 12.2 g of benzoic acid is dissolved in 100 g of water, the freezing point of solution was found to be $$-$$0.93$$^\circ$$C (Kf(H2O) = 1.86 K kg mol$$-$$1). The number (n) of benzoic acid molecules associated (assuming 100% association) is ___________.