1
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
The stability of +1 oxidation state among Al, Ga, In and Tl increases in the sequence
A
Al < Ga < In < Tl
B
Tl < In < Ga < Al
C
In < Tl < Ga < Al
D
Ga < In < Al < Tl
2
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
The variation of the boiling points of the hydrogen halides is in the order HF > HI > HBr > HCl.

What explains the higher boiling point of hydrogen fluoride?
A
There is strong hydrogen bonding between HF molecules.
B
The bond energy of HF molecules is greater than in other hydrogen halides.
C
The effect of nuclear shielding is much reduced in fluorine which polarises the HF molecule.
D
The electronegativity of fluorine is much higher than for other elements in the group.
3
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
Strong reducing behavior of H3PO2 is due to
A
high electron gain enthalpy of phosphorus
B
high oxidation state of phosphorus
C
presence of two $$-$$OH groups and one P$$-$$H bond
D
presence of one $$-$$OH group and two P$$-$$H bonds.
4
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
The formation of the oxide ion, O2$$-$$(g) from oxygen atom requires first an exthermic and then an endothermic step as shown below:
O(g) + e$$-$$ $$ \to $$ O$$-$$(g);  $$\Delta $$fHo = $$-$$141 kJ mol$$-$$1

O$$-$$(g) + e$$-$$ $$ \to $$ O2$$-$$(g);  $$\Delta $$fHo = +780 kJ mol$$-$$1

Thus, process of formation of O2$$-$$ is isoelectronic with neon. It is due to the fact that,
A
O$$-$$ ion has comparatively smaller size than oxygen atom
B
oxygen is more electronegative
C
addition of electron in oxygen results in larger size of the ion
D
electron repulsion outweighs the stability gained by achieving noble gas configuration.
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12