1
JEE Main 2021 (Online) 16th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
The characteristics of elements X, Y and Z with atomic numbers, respectively, 33, 53 and 83 are :
A
X and Y are metalloids and Z is a metal.
B
X and Z are non-metals and Y is a metalloid.
C
X is a metalloid, Y is a non-metal and Z is a metal.
D
X, Y and Z are metals.
2
JEE Main 2021 (Online) 16th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Which of the following is least basic?
A
$${(C{H_3}CO)_2}\mathop N\limits^{..} H$$
B
$$(C{H_3}CO)\mathop N\limits^{..} H{C_2}{H_5}$$
C
$${({C_2}{H_5})_3}\mathop N\limits^{..} $$
D
$${({C_2}{H_5})_2}\mathop N\limits^{..} H$$
3
JEE Main 2021 (Online) 16th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Ammonolysis of Alkyl halides followed by the treatment with NaOH solution can be used to prepare primary, secondary and tertiary amines. The purpose of NaOH in the reaction is :
A
to remove acidic impurities
B
to remove basic impurities
C
to activate NH3 used in the reaction
D
to increase the reactivity of alkyl halide
4
JEE Main 2021 (Online) 16th March Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
The secondary structure of protein is stabilised by:
A
Hydrogen bonding
B
glycosidic bond
C
Peptide bond
D
van der Waals forces
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