1
JEE Main 2021 (Online) 24th February Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Consider the elements Mg, Al, S, P and Si, the correct increasing order of their first ionization enthalpy is :
A
Al < Mg < Si < S < P
B
Al < Mg < S < Si < P
C
Mg < Al < Si < S < P
D
Mg < Al < Si < P < S
2
JEE Main 2021 (Online) 24th February Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Out of the following, which type of interaction is reponsible for the stabilisation of $$\alpha $$-helix structure of proteins ?
A
Covalent bonding
B
vander Waals forces
C
Ionic bonding
D
Hydrogen bonding
3
JEE Main 2021 (Online) 24th February Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Which of the following compound gives pink colour on reaction with phthalic anhydride in conc. H2SO4 followed by treatment with NaOH ?
A
JEE Main 2021 (Online) 24th February Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 111 English Option 1
B
JEE Main 2021 (Online) 24th February Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 111 English Option 2
C
JEE Main 2021 (Online) 24th February Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 111 English Option 3
D
JEE Main 2021 (Online) 24th February Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 111 English Option 4
4
JEE Main 2021 (Online) 24th February Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Given below are two statements :

Statement I : Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame.

Statement II : Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame.

In the light of the above statements, choose the most appropriate answer from the options given below.
A
Statement I is true but Statement II is false
B
Statement I is false but Statement II is true
C
Both Statement I and Statement II are false
D
Both Statement I and Statement II are true
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