general science

Chemistry MCQ Questions and Answers page - 1

1.

What happens when a chemical bond is formed ?

Answer/ Hint       Comment On Question

Answer : A

Explanation :

Energy is always absorbed when a chemical bond is formed and energy is leleased when a chemical bond breaks.

2.

“All the four quantum numbers of two electrons in an atom are not the same.” It is the law of –

Answer/ Hint       Comment On Question

Answer : B

Explanation :

Exclusion principle of pauli states that  “All the four quantum numbers of two electrons in an atom are not the same.”

3.

The atomic number of carbon is 6 and its atomic mass is 12. How many protons are there in the nucleus of carbon ?

Answer/ Hint      

Answer : A

Explanation :

4.

Nucleus of an atom consists of

Answer/ Hint      

Answer : C

Explanation :

5.

Isobars are lines joining places having equal

Answer/ Hint       Comment On Question

Answer : B

Explanation :

Isobars are imaginary lines joining the places having equal values of pressure. For convenience all the pressure are converted to sea level. The spacing of isobars indicates the rate and direction of the pressure.

6.

What is the element that is in the highest percentage in the composition of the earth ?

Answer/ Hint      

Answer : B

Explanation :

7.

Milk is a natural

Answer/ Hint      

Answer : B

Explanation :

8.

Sea water can be purified by the process of

Answer/ Hint      

Answer : A

Explanation :

9.

The residue left after extracting juice from sugar-beet and sugarcane is called

Answer/ Hint      

Answer : B

Explanation :

10.

The isotope of Uranium used in atomic reactors is

Answer/ Hint      

Answer : A

Explanation :

11.

The process of removing calcium and magnesium from hard water is known as

Answer/ Hint      

Answer : D

Explanation :

12.

The national Chemical Laboratory (India) is located in

Answer/ Hint      

Answer : D

Explanation :

13.

Which of the following is not a nucleon ?

Answer/ Hint      

Answer : D

Explanation :

14.

What particles move around the nucleus of an atom and are negatively charged ?

Answer/ Hint      

Answer : A

Explanation :

15.

The number of neutrons present in an element having mass number 226 and atomic number 88 is  :

Answer/ Hint      

Answer : B

Explanation :

16.

An atom of an element has atomic number 17 and mass number 36. The number of neutrons in its nucleus is

Answer/ Hint      

Answer : B

Explanation :

17.

Select the one which is not a mixture  :

Answer/ Hint      

Answer : D

Explanation :

18.

The total energy of revolving electron in an atom

Answer/ Hint      

Answer : C

Explanation :

The total energy of a revolving electron in any orbit is the sum of its kinetic and potential energies. Energy of an electron at infinite distance from the nucleus is zero. As an electron approaches the nucleus, the electron attraction increases and the energy of electron decreases and thus becomes negative. Thus, it can never be positive.

19.

Conduction band electrons have more mobility than holes because they

Answer/ Hint      

Answer : B

Explanation :

20.

The mass number of a nucleus is

Answer/ Hint      

Answer : D

Explanation :

21.

The chemical behaviour of an atom depends upon

Answer/ Hint      

Answer : C

Explanation :

22.

The electronic configuration of an atom having atomic number ‘20’ is

Answer/ Hint      

Answer : C

Explanation :

23.

A mixture of water and alcohol can be separated by

Answer/ Hint      

Answer : D

Explanation :

24.

The oxidation number of nickel in  K4[Ni(CN)4]  is 

Answer/ Hint      

Answer : A

Explanation :

25.

The orientation of an atomic orbital is governed by

Answer/ Hint      

Answer : B

Explanation :

26.

The value of Avogadro Number is

Answer/ Hint      

Answer : B

Explanation :

27.

The weight of 6.023 × 1022  atoms of carbon is

Answer/ Hint      

Answer : A

Explanation :

28.

Suspension particles have the size between

Answer/ Hint      

Answer : A

Explanation :

29.

The value of gas constant R in Ergs deg-1 mole-1 is

Answer/ Hint      

Answer : A

Explanation :

30.

Rutherford’s scattering experiment proved the presence of

Answer/ Hint      

Answer : D

Explanation :

31.

When a metal is heated in a flame, the electrons absorb energy and jump to higher energy state. On coming back to the lower energy state, they emit light which we can observe in

Answer/ Hint      

Answer : C

Explanation :

32.

Which one of the following has greatest mass ?

Answer/ Hint      

Answer : C

Explanation :

33.

A colloidal system in which a liquid is dispersed in a liquid is called

Answer/ Hint      

Answer : B

Explanation :

34.

Heavy water is so called because it contains

Answer/ Hint      

Answer : A

Explanation :

35.

The nuclear particle having no mass and no charge, but only spin is

Answer/ Hint      

Answer : B

Explanation :

36.

In a period from Li to F, ionisation potential

Answer/ Hint      

Answer : A

Explanation :

37.

Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has

Answer/ Hint      

Answer : C

Explanation :

38.

‘Atomic theory’ of matter was given by

Answer/ Hint      

Answer : B

Explanation :

39.

Which among the following is a covalent compound ?

Answer/ Hint      

Answer : D

Explanation :

40.

Which of the following is the maximum number of electrons that can be present in M-shell ?

Answer/ Hint      

Answer : C

Explanation :

41.

How many neutrons are there in   92U238  atom ?

Answer/ Hint      

Answer : C

Explanation :

42.

When cathode rays strike a target of high atomic weight, they give rise to

Answer/ Hint      

Answer : C

Explanation :

43.

Atoms of different elements have

Answer/ Hint      

Answer : C

Explanation :

44.

Nucleons are regarded as composites sub-particles known as

Answer/ Hint      

Answer : B

Explanation :

45.

In the periodic table of elements, on moving from left to right across a period, the atomic radius

Answer/ Hint      

Answer : A

Explanation :

46.

Number of neutrons in an atom of hydrogen is

Answer/ Hint      

Answer : B

Explanation :

47.

Who developed the model of atomic structure ?

Answer/ Hint      

Answer : A

Explanation :

48.

When a bond is formed is formed between two atoms, the energy of the system will

Answer/ Hint      

Answer : C

Explanation :

49.

Muddy water is treated with alum in purification process, it is termed as :

Answer/ Hint      

Answer : D

Explanation :

50.

Which one of the following is also know as solution ?

Answer/ Hint      

Answer : B

Explanation :

51.

A solution is

Answer/ Hint      

Answer : A

Explanation :

52.

Which of the following particles has the dual nature of particle wave ?

Answer/ Hint      

Answer : A

Explanation :

53.

Atoms having the same number of protons but different number of neutrons are called :

Answer/ Hint      

Answer : A

Explanation :

54.

Iron filing can be separated from a heterogenous mixture using the technique of :

Answer/ Hint      

Answer : B

Explanation :

55.

The strongest oxidizing agent among the following is :

Answer/ Hint      

Answer : C

Explanation :

56.

The number of hydrogen bonds between guanine and cytosine in DNA is

Answer/ Hint      

Answer : B

Explanation :

57.

J.J. Thomson’s proposed model of action is generally called  __________ model.

Answer/ Hint      

Answer : B

Explanation :

58.

Atomic number of an atom gives the number of which of the following ?

Answer/ Hint      

Answer : B

Explanation :

59.

In which of the following ions, the colour is not due to d-d transition ?

Answer/ Hint      

Answer : C

Explanation :

60.

Which one of the following has a maximum tendency to form M3 ion ?

Answer/ Hint      

Answer : A

Explanation :

61.

The molecular mass of a gas is

Answer/ Hint      

Answer : A

Explanation :

62.

Chemical properties of isotopes

Answer/ Hint      

Answer : A

Explanation :

63.

Two electrons in an orbital are differentiated by which of the following ?

Answer/ Hint      

Answer : B

Explanation :

64.

Isobars have  _______ .

Answer/ Hint      

Answer : A

Explanation :

65.

Which among the following will be a negative ion ?

Answer/ Hint      

Answer : B

Explanation :

66.

The relation between bond length and bond energy is

Answer/ Hint      

Answer : C

Explanation :

67.

Electrons in the highest energy level of an atom are called  ________ .

Answer/ Hint      

Answer : C

Explanation :

68.

What happens when one S and one P orbital are hybridized ?

Answer/ Hint      

Answer : B

Explanation :

69.

Electrons move around the nucleus in  _________  motion.

Answer/ Hint      

Answer : C

Explanation :

70.

_________  character of a bond between two atoms is greater if the difference in their electro negativities is lesser.

Answer/ Hint      

Answer : D

Explanation :

71.

Two gaseous molecules can react only when they have same  _______ .

Answer/ Hint      

Answer : D

Explanation :

72.

The subatomic particle that does not have any electric charge is a / an  _________ .

Answer/ Hint      

Answer : C

Explanation :

73.

What are the components of nucleus of an atom ?

Answer/ Hint      

Answer : B

Explanation :

74.

What is the mass of one mole of a substance in grams is called ?

Answer/ Hint      

Answer : D

Explanation :

75.

What are isobars ?

Answer/ Hint      

Answer : B

Explanation :

76.

Process of gaining electrons is known as  _________ .

Answer/ Hint      

Answer : B

Explanation :

77.

How many isotopes of Hydrogen element are there ?

Answer/ Hint      

Answer : B

Explanation :

78.

Soil is an example of which of the following ?

Answer/ Hint      

Answer : D

Explanation :

79.

An atom is  _________ .

Answer/ Hint      

Answer : C

Explanation :

80.

Which of the following is NOT positively charged ?

Answer/ Hint      

Answer : D

Explanation :

81.

How many moles are present on 36 gm of water ?

Answer/ Hint      

Answer : B

Explanation :

82.

What is the mass of 4 mole of aluminium atoms ?

Answer/ Hint      

Answer : B

Explanation :

Chemistry MCQ Questions and Answers page - 1
Next >>