chemistry MCQs - 12th class Chapter 02 Mcqs

1

The elements of group IA, except for hydrogen, are known as what?

A

Halogens

B

Noble Gases

C

Alkali metals

D

Alkaline-earth metals

2

Why are Group IA and IIA elements called s-block elements?

A

Their outermost electrons are in p-orbitals

B

Their outermost electrons are in s-orbitals

C

They are soft metals

D

They are found in sand

3

The name 'alkali' is derived from which language?

A

Latin

B

Greek

C

French

D

Arabic

4

Which of the following is the most abundant alkali metal in the Earth's crust?

A

Lithium

B

Sodium

C

Rubidium

D

Caesium

5

Alkaline-earth metals belong to which group of the periodic table?

A

Group IA

B

Group IIA

C

Group IIIA

D

Group IVA

6

How many electrons do alkali metals have in their valence shell?

A

One

B

Two

C

Three

D

Four

7

What charge do alkaline-earth metals typically form in their ionic compounds?

A

+1

B

+2

C

-1

D

-2

8

Which of the following is a common mineral of Lithium?

A

Carnallite

B

Dolomite

C

Spodumene

D

Beryl

9

The chemical formula for Rock Salt (Halite) is:

A

KCl

B

NaCl

C

CaCl2

D

MgCl2

10

Due to their high reactivity, alkali metals are never found in what state in nature?

A

Combined state

B

Solid state

C

Free state

D

Liquid state

11

Magnesium is an essential constituent of which biological molecule?

A

Hemoglobin

B

Chlorophyll

C

DNA

D

Starch

12

Which element is of great interest due to its radioactive nature?

A

Barium

B

Strontium

C

Radium

D

Beryllium

13

Which property explains the peculiar behavior of Lithium?

A

Its large atomic radius

B

Its low charge density

C

Its small radius and high charge density

D

Its high electronegativity

14

Unlike other alkali metals, when burnt in air, Lithium forms only a:

A

Peroxide

B

Superoxide

C

Suboxide

D

Normal oxide

15

Lithium reacts with nitrogen to form:

A

Lithium azide

B

Lithium nitrate

C

Lithium nitride

D

Lithium nitrite

16

Which alkaline-earth metal is almost as hard as iron?

A

Beryllium

B

Magnesium

C

Calcium

D

Barium

17

Which is the only Group IIA metal that reacts with alkalies to produce hydrogen?

A

Magnesium

B

Calcium

C

Strontium

D

Beryllium

18

The reducing power of an element is primarily dependent on its:

A

Electron affinity

B

Electronegativity

C

Ionization energy

D

Atomic size

19

When sodium reacts with an excess of oxygen, it forms:

A

Sodium oxide

B

Sodium superoxide

C

Sodium peroxide

D

Sodium suboxide

20

Potassium reacts with oxygen to form what?

A

Potassium oxide

B

Potassium peroxide

C

Potassium superoxide

D

Potassium suboxide

21

The reaction of alkali metals with water is highly:

A

Endothermic

B

Exothermic

C

Slow

D

Reversible

22

Alkali metals react with halogens to form what?

A

Covalent halides

B

Ionic halides

C

Complex halides

D

Double halides

23

When heated, all Group II-A elements react with nitrogen to give:

A

Nitrides

B

Nitrates

C

Azides

D

Nitrites

24

The solubility of alkaline-earth metal hydroxides in water generally:

A

Decreases down the group

B

Increases down the group

C

Remains constant

D

Is zero

25

Which of the following oxides is amphoteric?

A

CaO

B

MgO

C

BeO

D

BaO

26

LiOH decomposes on heating, while other alkali metal hydroxides are:

A

Also decomposed

B

Stable to heat

C

More reactive

D

Less soluble

27

The carbonates of alkaline-earth metals are generally:

A

Soluble in water

B

Very slightly soluble in water

C

Gaseous

D

Liquid

28

Decomposition of sodium nitrate ($NaNO_3$) produces sodium nitrite ($NaNO_2$) and what else?

A

Nitrogen dioxide

B

Nitrogen gas

C

Oxygen gas

D

Nitrous oxide

29

The solubility of sulphates of alkaline-earth metals:

A

Increases down the group

B

Remains the same

C

Decreases down the group

D

Is always high

30

What is the chemical formula for Gypsum?

A

$CaSO_4$

B

$CaSO_4.H_2O$

C

$CaSO_4.2H_2O$

D

$(CaSO_4)_2.H_2O$

31

Heating gypsum above 100°C produces a substance known as:

A

Cement

B

Plaster of Paris

C

Dead burnt plaster

D

Anhydrite

32

In the commercial preparation of sodium, what is added to NaCl to lower its melting point?

A

$CaCl_2$

B

$MgCl_2$

C

$KCl$

D

$LiCl$

33

In Down's cell for sodium extraction, the anode is made of:

A

Iron

B

Copper

C

Graphite

D

Steel

34

During the electrolysis in Down's cell, sodium is formed at the:

A

Anode

B

Cathode

C

Iron screen

D

Dome

35

Sodium hydroxide is commercially prepared by the electrolysis of:

A

Molten NaCl

B

Aqueous solution of NaCl

C

Sodium carbonate solution

D

Sodium sulphate solution

36

In the Diaphragm cell, what is produced at the anode?

A

Hydrogen

B

Sodium

C

Oxygen

D

Chlorine

37

The purpose of the asbestos diaphragm in the Nelson Cell is to:

A

Separate hydrogen and oxygen

B

Keep the brine warm

C

Keep chlorine and hydroxide ions separate

D

Filter the solution

38

A suspension of $Mg(OH)_2$ in water is called:

A

Lime water

B

Milk of magnesia

C

Baryta water

D

Slaked lime

39

Gypsum is applied to agricultural soils as a source of:

A

Nitrogen and Phosphorus

B

Potassium and Iron

C

Calcium and Sulphur

D

Magnesium and Carbon

40

Plaster that is formed from anhydrous calcium sulphate which absorbs water slowly is called:

A

Cement Plaster

B

Hard Finish Plaster

C

Dead burnt plaster

D

Surgical Plaster

41

What percentage of gypsum is added during the grinding of clinker to make cement?

A

2%

B

5%

C

10%

D

15%

42

Lime (CaO) is used in agriculture to:

A

Increase soil acidity

B

Neutralize acidic soils

C

Provide nitrogen

D

Increase soil moisture

43

The process of reacting lime with water is known as:

A

Hydration

B

Decomposition

C

Slaking of lime

D

Neutralization

44

Ordinary mortar is a mixture of slaked lime, water, and what other component?

A

Clay

B

Gravel

C

Sand

D

Cement

45

When lime is heated with coke at 2800°C, what is produced?

A

Calcium oxide

B

Calcium silicate

C

Calcium carbonate

D

Calcium carbide

46

Which of the following is a mineral of potassium?

A

Spodumene

B

Halite

C

Carnallite

D

Dolomite

47

Which alkali metal does not form a bicarbonate at room temperature?

A

Sodium

B

Potassium

C

Lithium

D

Rubidium

48

The decomposition of lithium carbonate ($Li_2CO_3$) produces lithium oxide and:

A

Carbon monoxide

B

Oxygen

C

Carbon dioxide

D

Nitrogen

49

Which compound is used in breathing equipment for mountaineers and in spacecraft?

A

$Li_2O$

B

$Na_2O_2$

C

$KO_2$

D

$Rb_2O_2$

50

Calcium is an essential constituent of all the following except:

A

Bones

B

Teeth

C

Sea-shells

D

Chlorophyll