JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyRecall

JEE Main 26 February 2021, Shift 2, Chemistry Q39

Question 39 of 90 in this shift, Chemistry question 9 of 30, Section A.

Calgon is used for water treatment. Which of the following statement is NOT true about Calgon ?

(1)Calgon contains the $2^{nd}$ most abundant element by weight in the Earth's crust.Official answer
(2)It is polymeric compound and is water soluble.
(3)It is also known as Graham's salt.
(4)It doesnot remove $\mathrm{Ca^{2+}}$ ion by precipitation.

Official answer

Option 1

NTA final key.

Chapter: The s-Block Elements
Topic: Hydrogen and Hydrides
Idea tested: Calgon's Method for Permanent Hardness

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.