JEE Main 27 August 2021, Shift 1, Chemistry Q38

Question 38 of 90 in this shift, Chemistry question 8 of 30, Section A.

The number of water molecules in gypsum, dead burnt plaster and plaster of Paris, respectively are :

(1)2, 0 and 1
(2)0.5, 0 and 2
(3)5, 0 and 0.5
(4)2, 0 and 0.5Official answer

Official answer

Option 4

NTA final key.

Chapter: The s-Block Elements
Topic: s-Block Elements
Idea tested: Gypsum and Plaster of Paris

Same idea in other shifts

Asked 2× in all

18 Mar 2021, Shift 1 · Q37Match List - I with List - II : List - I (a) $\mathrm{Ca(OCl)_2}$ (b) $\mathrm{CaSO_4\cdot\frac{1}{2}H_2O}$ (c) CaO (d) $\mathrm{CaCO_3}$ …EasyMatch the list

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.