1 kg of 0.75 molal aqueous solution of sucrose can be cooled up to $$-$$4$$^\circ$$C before freezing. The amount of ice (in g) that will be separated out is __________. (Nearest integer)
[Given : Kf(H2O) = 1.86 K kg mol$$-$$1]
Your Input ________
Answer
Correct Answer is 518
Explanation
Let mass of water initially present = x gm
$$\Rightarrow$$ Mass of sucrose = (1000 $$-$$ x) gm
Of the following four aqueous solutions, total number of those solutions whose freezing point is lower than that of 0.10 M C2C5OH is __________ (Integer answer)
(i) 0.10 M Ba3(PO4)2
(ii) 0.10 M Na2SO4
(iii) 0.10 M KCl
(iv) 0.10 M Li3PO4
Your Input ________
Answer
Correct Answer is 4
Explanation
As 0.1 M C2H5OH is non-dissociative and rest all salt given are electrolyte so in each case effective molarity > 0.1 so each will have lower freezing point.
4
JEE Main 2021 (Online) 27th July Evening Shift
Numerical
In a solvent 50% of an acid HA dimerizes and the rest dissociates. The van't Hoff factor of the acid is __________ $$\times$$ 10$$-$$2.