set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

One gram of which of the following contains largest number of oxygen atoms?

a) O₂

b) O₃

c) O

d) All contains same

Question : 2

What is the number of water molecules present in a tiny drop of water ( volume 0.0018 ml ) at room temperature?

a) 6.023 × 10¹⁹

b) 4.184 × 10¹⁸

c) 4.84 × 10¹⁷

d) 6.023 × 10²³

Question : 3

Which of the following is not a subatomic particle?

a) Proton

b) Deuteron

c) Neutron

d) Electron

Question : 4

Which of the following statement about molecular structure is correct?

a) Electron and proton are inside the nucleus and neutron revolve around the nucleus

b) Proton and neutron are inside the nucleus and electrons revolve around the nucleus

c) Neutron and electron are found inside the nucleus and protons revolves around the nucleus

d) Proton, neutron and electron all are inside the nucleus

Question : 5

Which one of the following laws explains the formation of carbon monoxide and carbon dioxide from carbon and oxygen?

a) Law of multiple proportions

b) Law of reciprocal proportions

c) Law of conservation of mass

d) Law of difinite proportions

Question : 6

While performing cathode ray experiments, it was observed that there was no passage of electric current under normal conditions. Which of the following can account for this observation ?

a) Carbon dioxide is present in air

b) Air is a poor conductor of electricity under normal conditions

c) Dust particles are present in air

d) None of these