JEE Main 2019PhysicsThermal Properties of MatterMediumMCQ

JEE Main 2019 — Thermal Properties of Matter Question with Solution

JEE Main 2019 (08 Apr Shift 1)

Question

A thermally insulated vessel contains 150 g of water at 0°C . Then the air from the vessel is pumped out adiabatically. A fraction of water turns into ice and the rest evaporates at 0°C itself. The mass of evaporated water will be closest to: (Latent heat of vaporization of water =2.10×106 J kg-1 and Latent heat of Fusion of water =3.36×105 J kg-1 )

Choose an option

Show full solutionCorrect option: B
Correct answer
B20 g

Step-by-step explanation

Suppose m grams of water evaporate. Then, heat required
ΔQreq=mLv
Mass that converts into ice =150-m
Heat released in the process,
ΔQrel=150-mLf
Now, ΔQrel=ΔQreq
150-mLf=mLv
mLf+Lv=150 Lf
m=150LfLf+Lv
m=20 g

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About this question

This is a previous-year question from JEE Main 2019, covering the Thermal Properties of Matter chapter of Physics. 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.