JEE Main 2020ChemistrySolutionsEasyNumerical

JEE Main 2020 — Solutions Question with Solution

JEE Main 2020 (09 Jan Shift 1)

Question

How much amount of NaCl should be added to 600 g of water ρ=1.00g/mL to decrease the freezing point of water to -0.2 oC? ________. (The freezing point depression constant for water =2 K kgmol-1 )

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Show full solutionCorrect answer: 1.74
Correct answer
1.74

Step-by-step explanation

∆Tf=0.2°C
∆Tf= ikfm
0.2=2×2×ω58.5×1000600
ω=0.2×58.5×6001000×4=1.2×58.540=01.76 g

Freezing point depression is the phenomena that describes why adding a solute to a solvent results in the lowering of the freezing point of the solvent.

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About this question

This is a previous-year question from JEE Main 2020, covering the Solutions chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.