1
JEE Main 2021 (Online) 18th March Morning Shift
Numerical
+4
-1
2 molal solution of a weak acid HA has a freezing point of 3.885$$^\circ$$C. The degree of dissociation of this acid is ___________ $$\times$$ 10$$-$$3. (Round off to the Nearest Integer).

[Given : Molal depression constant of water = 1.85 K kg mol$$-$$1 Freezing point of pure water = 0$$^\circ$$ C]
2
JEE Main 2021 (Online) 17th March Evening Shift
Numerical
+4
-1
A 1 molal K4Fe(CN)6 solution has a degree of dissociation of 0.4. Its boiling point is equal to that of another solution which contains 18.1 weight percent of a non electrolytic solute A. The molar mass of A is __________ u. (Round off to the Nearest Integer). [Density of water = 1.0 g cm$$-$$3 ]
3
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 ]
4
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).