Top 1000+ Solved Chemistry MCQ Questions Answer
Q. Which of the following statements is true about Methane?
a. It is widely used as a fuel.
b. It is a major component of bio-gas and Compressed Natural Gas.
c. It has a formula CH4.
d. All of the above
Q. Sulphur dioxide level in the atmosphere can be reduced by using -
a. more efficient car engines
b. catalytic converters in industry
c. static electricity to attract it in factory chimneys
d. low - sulphur fuels
Q. Chlorine atom and chloride ions -
a. Have an equal number of protons
b. Have an equal number of electrons
c. Unequal number neutrons
d. reacts spontaneously with water
Q. An atom of an element with mass number 23 and atomic number 11 will have-
a. 11 neutrons, 12 protons and 11 electrons
b. 11 protons, 12 neutrons and 11 electrons
c. 11 protons, 12 electrons and 11 neutrons
d. 23 protons and 11 electrons
Q. Atoms of different elements have -
a. same atomic number and same electronic configuration
b. different atomic number and same eletronic configuration
c. different atomic number and different number of valence electrons
d. same number of electrons and neutrons
Q. The molecular mass of a gas is –
a. twice its vapour pressure
b. equal to its vapour pressure
c. half its vapour pressure
d. not related to its vapour pressure
Q. Hydrogen is not found in atmosphere because –
a. it is highly inflammable
b. it is the lightest gas
c. it is absorbed by plants
d. it immediately combines with oxygen to form water
Q. The mass number of a nucleus is -
a. always less than its atomic number
b. the sum of the number of protons and neutrons present in the nucleus
c. always more than the atomic weight
d. a fraction
Q. What are transition elements?
a. Elements whose two outermost shells are incomplete
b. Elements which possess properties of both, metals and non-metals
c. They have eight electrons in the outermost shell
d. Elements whose three outermost shells are incomplete
Q. A balloon filled with helium rises in air because –
a. air exerts an upward force on the balloon
b. the balloon is weightless
c. helium is less dense than air
d. helium pushes down on the air below the balloon
Q. Aqua regia is a 1 : 3 mixture, by volume, of –
a. conc, nitric acid and conc. hydrochloric acid
b. conc. hydrochloric acid and conc. nitric acid
c. con nitric acid and cone. sulphuric acid
d. cone. sulphuric acid and cone. nitric acid
Q. The freezer in a refrigerator is fitted near the top –
a. to keep it away from hot compressor which is nearer to the bottom
b. because of convenience
c. it facilitates convection currents
d. to minimise power consumption
Q. What happens when a chemical bond is formed?
a. energy is always absorbed
b. energy in always released
c. more energy is released than is absorbed
d. energy is neither released nor absorbed
Q. Silver nitrate solution is kept in brown bottles in laboratory because -
a. it reacts with ordinary white bottles
b. brown bottles stops the passage of light through it
c. brown bottles do not react with it
d. brown bottles react with it
Q. In upper layer of atmosphere ozone is formed by -
a. the action of ultraviolet rays on oxygen
b. the combination of oxygen molecules
c. subjecting oxygen to high pressure
d. the action of nitrogen on oxygen in atmosphere