1
JEE Main 2021 (Online) 20th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Which one of the following species doesn't have a magnetic moment of 1.73 BM, (spin only value)?
A
O$$_2^ + $$
B
CuI
C
[Cu(NH3)4]Cl2
D
O$$_2^ - $$
2
JEE Main 2021 (Online) 20th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Which one of the following statements is not true about enzymes?
A
Enzymes are non-specific for a reaction and substrate.
B
Almost all enzymes are proteins.
C
Enzymes work as catalysts by lowering the activation energy of a biochemical reaction.
D
The action of enzymes is temperature and pH specific.
3
JEE Main 2021 (Online) 20th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
The hybridisations of the atomic orbitals of nitrogen in NO$$_2^ - $$, NO$$_2^ + $$ and NH$$_4^ + $$ respectively are.
A
sp3, sp2 and sp
B
sp, sp2 and sp3
C
sp3, sp and sp2
D
sp2, sp and sp3
4
JEE Main 2021 (Online) 20th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Benzene on nitration gives nitrobenzene in presence of HNO3 and H2SO4 mixture, where :
A
both H2SO4 and HNO3 act as a bases
B
HNO3 acts as an acid and H2SO4 acts as a base
C
both H2SO4 and HNO3 act as an acids
D
HNO3 acts as a base and H2SO4 acts as an acid
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