chemistry MCQs - 11th class Chapter 01 Mcqs

1

The concept that matter is composed of indivisible particles called 'atomos' was first proposed by

A

John Dalton

B

Democritus

C

J. Berzelius

D

Soddy

2

Which of the following is considered a fundamental particle of an atom?

A

Hypron

B

Neutrino

C

Proton

D

Anti-neutrino

3

Who is credited with developing the system of giving elements a symbol?

A

John Dalton

B

Democritus

C

J. Berzelius

D

Avogadro

4

An ordinary optical microscope cannot be used to see an atom because an atom is smaller than the

A

beam of electrons

B

wavelength of visible light

C

wavelength of X-rays

D

size of a proton

5

The diameter of an atom is of the order of

A

0.2 cm

B

0.2 mm

C

0.2 nm

D

0.2 µm

6

The value of 1 amu (atomic mass unit) is equal to

A

1.661 x 10^-24 g

B

1.661 x 10^-27 kg

C

6.02 x 10^-23 kg

D

9.1 x 10^-31 kg

7

A molecule that consists of a single atom is called

A

Diatomic

B

Triatomic

C

Polyatomic

D

Monoatomic

8

Haemoglobin is an example of a

A

Micromolecule

B

Ionic compound

C

Macromolecule

D

Diatomic molecule

9

The formation of a cation (positive ion) from a neutral atom is always an

A

Exothermic process

B

Endothermic process

C

Spontaneous process

D

Non-spontaneous process

10

Which of the following is an example of a molecular ion?

A

SO4^2-

B

NH4^+

C

CO+

D

Na+

11

The standard for relative atomic mass is based on the mass of an atom of

A

Hydrogen-1

B

Oxygen-16

C

Carbon-12

D

Uranium-238

12

Isotopes are atoms of the same element with the same atomic number but different

A

Number of protons

B

Number of electrons

C

Mass numbers

D

Chemical properties

13

The phenomenon of isotopy was first discovered by

A

Soddy

B

Dalton

C

Aston

D

Democritus

14

How many isotopes does tin (Sn) have?

A

Three

B

Five

C

Nine

D

Eleven

15

Which of the following elements is mono-isotopic?

A

Carbon

B

Chlorine

C

Uranium

D

Gold

16

In mass spectrometry, a substance is first volatilized and then

A

condensed

B

ionized

C

neutralized

D

solidified

17

In a mass spectrometer, ions are separated based on their

A

charge only

B

mass only

C

mass to charge ratio (m/e)

D

velocity only

18

The mathematical relationship for m/e in a mass spectrometer is

A

m/e = H²r²/2E

B

m/e = Hr²/2E

C

m/e = H²r/2E

D

m/e = H²r/E

19

The average atomic mass of neon, as calculated from isotopic abundance, is approximately

A

20.00 amu

B

20.18 amu

C

21.00 amu

D

22.00 amu

20

The simplest formula that gives the whole number ratio between atoms in a compound is called

A

Molecular formula

B

Structural formula

C

Empirical formula

D

Condensed formula

21

What is the empirical formula of glucose (C6H12O6)?

A

CH2O

B

CHO

C

C2H4O2

D

C6H12O6

22

In combustion analysis, water vapor is absorbed by

A

50% KOH

B

Mg(ClO4)2

C

Silica gel

D

Concentrated H2SO4

23

In combustion analysis, carbon dioxide is absorbed by

A

50% KOH

B

Mg(ClO4)2

C

Anhydrous CaCl2

D

P2O5

24

The molecular formula is a simple integer multiple of the

A

Structural formula

B

Ionic formula

C

Empirical formula

D

Molar mass

25

The value of 'n' (the integer multiple) can be calculated as

A

Empirical mass / Molecular mass

B

Molecular mass / Empirical mass

C

Molar mass / Avogadro's number

D

Actual yield / Theoretical yield

26

The mass of a substance expressed in grams is called its

A

Atomic mass

B

Formula mass

C

Gram mass

D

Molar mass

27

One mole of any substance contains how many particles?

A

6.02 x 10^22

B

6.02 x 10^23

C

3.01 x 10^23

D

1.008

28

Avogadro's number is denoted by the symbol

A

B

N

C

A_N

D

N_A

29

The volume occupied by one mole of any ideal gas at STP is

A

22.414 cm³

B

2.24 dm³

C

22.414 dm³

D

224.14 dm³

30

The quantitative relationship between reactants and products in a balanced chemical equation is known as

A

Stoichiometry

B

Thermochemistry

C

Kinetics

D

Equilibrium

31

The reactant that is completely consumed in a reaction and controls the amount of product formed is the

A

Excess reactant

B

Limiting reactant

C

Catalyst

D

Product

32

The amount of product calculated from a balanced chemical equation is the

A

Actual yield

B

Percentage yield

C

Theoretical yield

D

Experimental yield

33

The efficiency of a chemical reaction is expressed by the

A

Theoretical yield

B

Actual yield

C

Percentage yield

D

Rate of reaction

34

Which property of isotopes differs?

A

Chemical properties

B

Number of protons

C

Position in periodic table

D

Properties which depend upon mass

35

Isotopes with even atomic masses and even atomic numbers are comparatively

A

rare

B

abundant

C

unstable

D

radioactive

36

Many elements have fractional atomic masses because they are the average masses of

A

isobars

B

isomers

C

isotopes

D

allotropes

37

The mass of one mole of electrons is approximately

A

1.008 mg

B

0.55 mg

C

0.184 mg

D

1.673 mg

38

The number of moles of CO2 which contain 8.0 g of oxygen is

A

0.25

B

0.50

C

1.0

D

1.50

39

One mole of SO2 contains

A

6.02x10^23 atoms of oxygen

B

18.1 x 10^23 molecules of SO2

C

6.02x10^23 atoms of sulphur

D

4 gram atoms of SO2

40

The volume occupied by 1.4 g of N2 at S.T.P is

A

2.24 dm³

B

22.4 dm³

C

1.12 dm³

D

112 cm³

41

A limiting reactant is the one which gives the

A

maximum amount of the product

B

minimum amount of the product

C

average amount of product

D

desired amount of product

42

How many atoms are in one molecule of Sulphuric Acid (H2SO4)?

A

6

B

7

C

8

D

5

43

The formation of a uninegative ion is generally an

A

endothermic process

B

exothermic process

C

adiabatic process

D

isothermal process

44

Cationic molecular ions are generally _______ than anionic ones.

A

less stable

B

more abundant

C

less abundant

D

heavier

45

The number of neutrons in the C-14 isotope is

A

6

B

7

C

8

D

14

46

Elements whose mass numbers are multiples of four are particularly

A

unstable

B

rare

C

abundant

D

radioactive

47

The pressure of vapours inside an ionization chamber of a mass spectrometer is kept very low, around

A

10^-6 to 10^-7 torr

B

10^-3 to 10^-4 torr

C

1 to 2 torr

D

760 torr

48

The number of atoms in a full stop is estimated to be around

A

two thousand

B

two million

C

two billion

D

two hundred

49

The empirical formula of benzene (C6H6) is

A

C2H2

B

C3H3

C

CH

D

C6H6

50

The atomic mass of chlorine is 35.453 amu, which is a fractional value due to

A

the presence of isotopes

B

instability of the nucleus

C

experimental error

D

its high reactivity