JEE Main 2021ChemistrySolid StateType Of Solids And Their PropertiesmediumMCQ

JEE Main 2021 — Solid State Question with Solution

From: JEE Main 2021 (Online) 20th July Morning Shift

Question

Given below are two statements. One is labelled as Assertion A nd the other is labelled as Reason R.

Assertion A : Sharp glass edge becomes smooth on heating it upto its melting point.

Reason R : The viscosity of glass decreases on melting.

Choose the most appropriate answer from the options given below.

Choose an option

Show full solutionCorrect option: B
Correct answer
BBoth A and R are true but R is NOT the correct explanation of A.

Step-by-step explanation

On heating the glass, it melts and takes up rounded shape at the edges, which has minimum surface area. This is due to the property of surface tension of liquids and not due to decrease in viscosity.

Viscosity generally decreases as the temperature increases.

Hence, both A and R are true but R is not the correct explanation of A.

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About this question

This is a previous-year question from JEE Main 2021, covering the Solid State 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.