Boric acid is an acid because its molecule________.

(a)

contains replaceable H⁺ ion

(b)

gives up a proton

(c)

combines with proton to form water molecule

(d)

accepts OH^- from water, releasing proton.

Which of the following metals has the largest abundance in the earth’s crust?

(a)

Aluminium

(b)

Calcium

(c)

Magnesium

(d)

Sodium

In diborane, the number of electrons that accounts for banana bonds is ________.

(a)

six

(b)

two

(c)

four

(d)

three

Oxidation state of carbon in its hydrides _______.

(a)

+4

(b)

-4

(c)

+3

(d)

+2

The repeating unit in silicone is_______.

(a)

SiO₂

(b)

(c)

(d)

The geometry at which carbon atom in diamond are bonded to each other is _______.

(a)

Tetrahedral

(b)

hexagonal

(c)

Octahedral

(d)

none of these

AlF₃ is soluble in HF only in the presence of KF. It is due to the formation of _________.

(a)

K₃[AIF₃H₃]

(b)

K₃[AiF₆]

(c)

AIH₃

(d)

K[AIF₃H]

Thermodynamically the most stable form of carbon is________.

(a)

Diamond

(b)

graphite

(c)

Fullerene

(d)

none of these

The stability of +1 oxidation state increases in the sequence ________.

(a)

Al < Ga < In < Tl

(b)

Tl < In < Ga < Al

(c)

In < Tl < Ga < Al

(d)

Ga< In < Al < Tl

Select the incorrect statement regarding B₂H₆.

(a)

It contains B-B ionic bond

(b)

Each boron is Sp³ hybridised

(c)

It has two types of hydrogen bonds

(d)

it is used as a reducing agent

Which one of the following compounds has similar structure to that of graphite?

(a)

Boron nitride

(b)

Boron Carbide

(c)

Aluminium Carbide

(d)

Aluminium Oxide

Graphite has _______.

(a)

2-d sheet structure

(b)

Vander waals force between successive layers of carbon sheets

(c)

Sp² hybridised carbon linked with other three carbon atoms in hexagonal planar structure

(d)

all the above

Which one is correct statement for zeolite?

(a)

Zeolites are aluminosilicates having three dimensional framework

(b)

Hydrate zeolites are used as ion exchangers in hardening of soft water

(c)

Zeolites are alumino silicates

(d)

all the above

Identify the electron - deficient species

(a)

(BH₃)₂

(b)

(SiH₃)₂

(c)

PH₃

(d)

(CH₃)₂

Boron compounds behave as Lewis acid, because of their _______.

(a)

ionisation property

(b)

acidic nature

(c)

covalent nature

(d)

electron deficient nature

On moving down the group 13, density ______

(a)

decreases

(b)

increases

(c)

First decreases then increases

(d)

remains same

Oxidation state exhibited by group 13 elements is ______

(a)

+1, +2 and +3

(b)

+1 and +3

(c)

+1 and +4

(d)

+2 +3 and +4

Aluminium is used for making alloys because of its _____

(a)

resistance to corrosion

(b)

poor conductivity

(c)

heaviness

(d)

all of these

Allotropy is due to ______.

(a)

difference in chemical properties

(b)

difference in the number of atoms in the molecules

(c)

difference in the arrangement of atoms in the molecules in the crystal

(d)

None of these

Silicones are ______.

(a)

ortho silicates

(b)

water repellent thermal insulators

(c)

both (a) and (b)

(d)

None of these