1
JEE Main 2019 (Online) 9th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
20 mL of 0.1 M H2SO4 solution is added to 30 mL of of 0.2 M NH4OH solution. The pH of the resultant mixture is : [pkb of NH4OH = 4.7].
A
5.2
B
9.0
C
5.0
D
9.4
2
JEE Main 2019 (Online) 9th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
According to molecular orbital theory, which of the following is true with respect to Li2+ and Li2$$-$$ ?
A
$$Li_2^ + $$ is unstable and $$Li_2^ - $$ is stable
B
$$Li_2^ + $$ is stable and $$Li_2^ - $$ unstable
C
Both are stable
D
Both are unstable
3
JEE Main 2019 (Online) 9th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Aluminium is usually found in +3 oxidation state. In contrast, thallium exists in + 1 and + 3 oxidation states. This is due to :
A
inert pair effect
B
diagonal relationship
C
lattice structure
D
lanthanoid contraction
4
JEE Main 2019 (Online) 9th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
In general, the properties that decrease and increase down a group in the periodic table, respectively, are :
A
Atomic Radius and Electronegativity
B
Electron Gain Enthalpy and Electronegativity.
C
Electronegativity and Atomic Radius.
D
Electronegativity and Electron Gain Enthalpy.
JEE Main Papers
2023
2021
EXAM MAP