MCQ on Physical and Chemical Changes

CBSE/NCERT 7th Class MCQ CBSE/NCERT 7th Class MCQ on Science

MCQ on Physical and Chemical Changes

  1. A change in which a substance undergoes a change in its shape, size, colour and state is called a

(A) Physical change

(B) Chemical change

(C) Biological change

(D) None of the above

 

  1. In substances, which of the following change is reversible?

(A) Physical change

(B) Chemical change

(C) Biological Change

(D) None of the above

 

  1. A film of brownish substance on piece of iron in presence of atmosphere and vapours is called

(A) Dust

(B) Rust

(C)Both A and B

(D) None of the above

 

  1. Complete the following equation.

Magnesium (Mg) + Oxygen (O2) à

(A) Magnesium Oxidation (Mg2O)

(B) Magnesium dioxide (MgO2)

(C) Magnesium oxide (MgO)

(D) None of the above

 

  1. On dissolving magnesium oxide in water it forms a new substance it is called……………

Magnesium oxide (MgO)+ Water (H2 O) –>

(A) Magnesium hydrochloric oxide (MgOH2)

(B) Magnesium oxidation {MGOH3]

(C) Magnesium dioxide [Mg (OH)]

(D) Magnesium hydroxide [Mg (OH)2]

 

  1. Rust is a common name for…………….. in chemistry.

(A) Deoxidation

(B) Ferric oxide

(C) Iron oxide

(D) Both B and D

 

7.Chemical formula/name for iron oxide is

(A) Fe2O3

(B) Fe3O2

(C) He 202

(D) None of the above

 

  1. A change in which one or more new substances are formed is called

(A) a Physical Change /Physical reaction

(B) a chemical change/chemical reaction

(C) a mechanical change/ Mechanical reaction

(D) a Electrical Change/ Electric reaction

 

  1. ………………substance is formed on burning of magnesium.

(A) Magnesium sulphate

(B) Magnesium hydroxide

(C) Magnesium oxide

(D) All of the above

 

  1. …………. substance is formed by mixing magnesium oxide with water.

(A) Magnesium hydroxide

(B) Magnesium oxide

(C) Oxide

(D) Base

 

Answers :-

1.(A)       2.(A)           3.(B)        4.(C)       5.(D)           6.(D)          7.(A)      8.(B)      9.(C)       10.(A)

 

  1. Which of the following is/are a/ an example of chemical change?

(A) Plastics

(B) Detergent

(C) Burning of leaves

(D) All of the above

 

  1. Which of the following change is possible during chemical change?
  • (a). Heat, light or ultra violet radiation may be given off or absorbed.
  • (b). Sounds may be produced.
  • (c). A change in smell may take place of a new smell may be given off.
  • (d). A colour change may take place.
  • (e). A gas may be formed.

Choose the correct option from the given statement?

(A) Option (a), (b), (c)

(B) Option (c), (d), (e)

(C) All options are correct

(D) None of the option is correct

 

  1. Which of the following option/s is correct regarding chemical change?
  • (a). Burning of coal, leaves and wood.
  • (b). Explosion of Firework.
  • (c). slice of an apple that change colour.

(A) Option (a) and (b)

(B) Option (c) only

(C) All options are correct

(D) None of the above

 

  1. ………………….layer in our atmosphere protects us from the harmful ultraviolet radiations which come from the sun.

(A) Ozone

(B) Krypton

(C) Hydrogen

(D) Argon

 

  1. Ozone layer in the atmosphere absorbs the Ultraviolet radiations and breaks down to ………

(A) Carbon dioxide

(B) Nitrogen

(C) Oxygen

(D) None of the above

 

  1. Which of the following layer acts as a protective shield against UV rays?

(A) Ozone layer

(B) Troposphere

(C) Stratosphere

(D) Ultraviolet Radiations

 

  1. Which of the following equation represents the process of rusting?
  • (a). Iron (Fe) + Oxygen (O2) + Water (H2O)à Rust (iron oxide (Fe2O3)
  • (b). Iron (Fe) + Oxygen (O2) + Water (H3O)à Rust (iron oxide (Fe2O4)
  • (c). Iron (Fe) + Oxygen (O) + Water (H2O)à Rust (iron oxide (Fe2O)

(A) Only (a) option

(B) Only (b) option

(C) Only (c) option

(D) None of the above

 

  1. The process of depositing a layer of zinc or chromium on iron is called ………………..

(A) Greasing

(B) Oiling

(C) Crystallisation

(D) Galvanization

 

  1. ……………is made by mixing iron with carbon and metals like chromium, nickel and manganese.

(A) Stainless steel

(B) Rubber

(C) Pipes

(D) Plastic

 

  1. Large crystals of pure substances can be formed from their solution. This process is called

(A) Galvanization

(B) Crystallization

(C) Both (A) and (B)

(D) None of the above

 

Answers:-

11.(D)    12.(C)     13.(C)      14.(A)        15.(C)         16.(A)        17.(A)        18.(D)       19.(A)      20.(B)