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.

Oxidation state of carbon in its hydrides _______.

(a)

+4

(b)

-4

(c)

+3

(d)

+2

The basic structural unit of silicates is _______.

(a)

\(\left( SiO_{ 3 } \right) ^{ 2- }\)

(b)

\(\left( SiO_{ 4 } \right) ^{ 2- }\)

(c)

\(\left( Sio \right) ^{ - }\)

(d)

\(\left( SiO_{ 4 } \right) ^{ 4- }\)

Which of these is not a monomer for a high molecular mass silicone polymer?

(a)

Me₃SiCl

(b)

PhSiCl₃

(c)

MeSiCl₃

(d)

Me₂SiCl₂

Which of the following statements is not correct?

(a)

Beryl is a cyclic silicate

(b)

Mg₂SiO₄ is an orthosilicate

(c)

SiO₄⁴⁻is the basic structural unit of silicates

(d)

Feldspar is not aluminosilicate

Duralumin is an alloy of ______.

(a)

Cu,Mn

(b)

Cu,Al,Mg

(c)

Al,Mn

(d)

Al,Cu,Mn,Mg

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

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

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

Elements of group 13 mainly form covalent compounds because ______

(a)

small size

(b)

electro negativity values are high

(c)

ionization energy is very high

(d)

both (a) and (c)

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

Borax is _______.

(a)

Na₂[B₄O₅(OH)₄).8H₂O

(b)

Na₂[B₄O₅(OH)₆).7H₂O

(c)

Na₂[B₄O₃(OH)₈].6H₂O

(d)

Na₂[B₄O₂(OH)₁₀).5H₂O

Describe briefly allotropism in p- block elements with specific reference to carbon.

What is catenation ? describe briefly the catenation property of carbon.

Give the structure of CO and CO₂.

How is boric acid extracted from borax?

Mention the physical properties of boranes.

What is burnt alum?

What is water gas equilibrium?

What are the uses of silicon tetra chloride?

What is inert pair effect?

Name the two important ores of Boron.

Give the uses of silicones.

Describe the structure of diborane.

Write a short note on hydroboration.

Give one example for each of the following
(i) icosogens
(ii) Tetragens
(iii) pnictogens
(iv) chalcogens

What happens to boranes at high temperatures?

How is aluminum chloride prepared from aluminum?

Describe the structure of graphite.

Describe the structure of carbon nanotubes.

Describe the structure of graphene.

Account for the following:
(i) CO is used in the extraction of metals.
(ii) CO is poisonous
(iii) CO₂ is used in referigeration

How will you identify borate radical?

How will you convert boric acid to boron nitride?

A hydride of 2nd period alkali metal (A) on reaction with compound of Boron (B) to give a reducing agent (C). Identify A, B and C.

CO is a reducing agent. Justify with an example.

What are the various methods by which carbon-di-oxide is prepared?

How are silicates classified? Give an example for each type of silicate.

Distinguish between diamond and graphite.