Physical and Chemical Changes Class 7 MCQ Science Chapter 5

Class 7 Science Chapter 5 MCQ Physical and Chemical Changes

MCQ on Physical and Chemical Changes Class 7

I. Multiple Choice Questions (1 Mark)

Select and write the most appropriate option out of the four options given

Question 1.
Which of the following are physical changes?
i) Souring of milk
ii) Dissolving sugar in water
iii) Setting curd from milk
iv) Stretching of a rubber band
A) (i) and (iii)
B) (i) and (ii)
C) (iii) and (iv)
D) (ii) and (iv)
Answer:
D) (ii) and (iv)

Question 2.
Select the incorrect statement.
A) A change in which substance undergoes a change in its physical properties is called a physical change.
B) A physical change is generally irreversible.
C) In physical change, no new substance is formed.
D) Both A and C
Answer:
B) A physical change is generally irreversible.

Question 3.
Select the odd one out.
A) Evaporation
B) Cutting of paper
C) Burning of paper
D) Condensation
Answer:
C) Burning of paper

Question 4.
Identify the physical-reversible changes.
i) Melting of wax
ii) Slaking of lime
iii) Plucking of leaves
iv) Condensation of steam
A) (i) and (iii)
B) (ii) and (iv)
C) (i) and (iv)
D) (ii) and (ii)
Answer:
C) (i) and (iv)

Question 5.
Identify the physical change that cannot be reversed.
A) Making of sugar solution
B) Inflating a balloon
C) Drying of clothes
D) Breaking of flower vase
Answer:
D) Breaking of flower vase

Question 6.
Which kind of change rusting of iron is ?
A) Physical change
B) Reversible change
C) Chemical change
D) Both B and C
Answer:
C) Chemical change

Question 7.
Select the correct statements.
i) During a chemical change, no’ new substance is formed.
ii) Chemical changes are generally reversible.
iii) Most of the chemical changes are irreversible and permanent.
iv) During a chemical change, chemical composition of a substance is changed.
A) (i) and (iii)
B) (iii) and (iv)
C) (ii) and (iv)
D) (i) and (ii)
Answer:
B) (iii) and (iv)

Question 8.
Which of the following are chemical changes?
i) Heating an iron blade
ii) Mixing baking soda with vinegar
iii) Making of a salt solution
iv) Burning of a magnesium ribbon
A) (i) and (iii)
B) (i) and (iv)
C) (ii) and (iv)
D) (ii) and (iii)
Answer:
C) (ii) and (iv)

Question 9.
A………… reactive element displaces a ………… reactive element from its salt solution.
A) more, more
B) less, more
C) more, less
D) less, less
Answer:
C) more, less

Question 10.
………… is deposited as a brown coating on the iron nails kept in copper sulphate solution.
A) Iron
B) Ferrous sulphate
C) Copper sulphate
D) Copper
Answer:
D) Copper

Question 11.
Which of the following represents a displacement reaction?
A) 2Mg+O₂ → 2 MgO
B) Fe+CuSO₄ → FeSO₄+Cu
C) MgO+H₂O→Mg(OH)₂
D) 2H₂+ O₂ → 2H₂O
Answer:
B) Fe+CuSO₄ → FeSO₄+Cu

Question 12.
Chemically, rust is
A) iron
B) ferrous sulphate
C) iron oxide
D) none of these
Answer:
C) iron oxide

Question 13.
On passing carbon dioxide gas, lime water turns milky due to the formation of
A) calcium oxide
B) calcium carbonate
C) calclum hydroxide
D) calcium.
Answer:
B) calcium carbonate

Question 14.
Galvanisation is a process in which
A) Iron is coated on zinc metal
B) zinc and iron are mixed in molten state
C) zinc is coated as a layer on iron
D) carbon is mixed with iron and heated.
Answer:
C) zinc is coated as a layer on iron

Question 15.
Observe the following reaction and tick the correct statement.
Iron sulphate solution + Copper → Copper sulphate solution + Iron
A) Green colour of the solution changes to blue colour.
B) Iron is less reactive than copper
C) Reaction will not take place.
D) None of these
Answer:
C) Reaction will not take place.

Question 16.
Curdling of milk is a ………… change
A) chemical
B) reversible
C) physical
D) all of these
Answer:
A) chemical

Question 17.
Which of the following is a chemical change?
A) Photosynthesis
B) Transpiration
C) Digestion
D) Both A and C
Answer:
D) Both A and C

Question 18.
Which of the following are both physical and chemical changes?
i) Burning of wood
ii) Burning of candle
iii) Burning of LPG
iv) Burning of biogas
A) (i) and (iv)
B) (ii) and (iv)
C) (i) and (iii)
D) (ii) and (iii)
Answer:
D) (ii) and (iii)

Question 19.
Which of the following is a balanced chemical reaction?
A) H₂+Cl₂ → HCl
B) Mg +O₂ → 2 MgO
C) 2Fe+O₂ → FeO
D) 2C+O₂ →2 CO
Answer:
D)  2C+O₂ →2 CO

Question 20.
Which of the following are molecules?
i) Ba
ii) H₂
iii) Mg
iv) CO₂
A) (i) and (ii)
B) (iii) and (iv)
C) (ii) and (iv)
D) All of these
Answer:
C) (ii) and (iv)

Question 21.
What is the chemical formula of rust ?
A) FeCO₂
B) Fe₂O₃
C) Fe
D) FeSO₄
Answer:
B) Fe₂O₃

Question 22.
…………….. gas is evolved when zinc reacts with dilute sulphuric acid.
A) Carbon dioxide
B) Hydrogen
C) Ammonia
D) Oxygen
Answer:
B) Hydrogen

Question 23.
Which of the following gases turn(s) lime water milky?
A) Carbon dioxide gas
B) Oxygen gas
C) Sulphur dioxide gas
D) Both (A) and (C)
Answer:
D) Both (A) and (C)

Question 24.
Fill in the blanks by observing the following chemical process:

Answer:
(A)

II. Fill in the blanks

1. When carbon dioxide is passed through lime water, it turns milky due to the formation of …………
Answer: Calcium Carbonate

2. The chemical nature of vinegar is …………
Answer: acidic

3. The chemical nature of baking soda is …………
Answer: basic

4. Bubbles of ………… gas with hissing sound are evolved on reaction between baking soda and lemon juice.
Answer: carbondioxide

5. Copper sulphate solution is ………… in colour.
Answer: blue

6. When an iron blade is dipped in copper sulphate solution, the colour of solution changes from ………… to ………… due to the formation of ………… and the surface of iron nail gets a brown coloured deposit of …………
Answer: blue, green, iron sulphate, copper

7. The air we breathe out is rich in …………
Answer: carbondioxide

8. When the ash formed by burning of magnesium in air is dissolved in water, ………… is formed.
Answer: magnesium hydroxide

9. The process of separation of crystals from a ………… solution on cooling, is called …………
Answer: Super saturated crystallisation

10. The change of state of a substance from solid to liquid and liquid to gas is a ………… change.
Answer: physical

11. ………… gas extinguishes fire.
Answer: carbondioxide

12. When carbon dioxide gas is passed through ………… it turns milky.
Answer: lime water

13. A new product ………… is formed, by the action of water and oxygen on iron.
Answer: rust (iron oxide)

14. Blue colour of the copper sulphate solution changes to green due to the formation of …………
Answer: Ferrous sulphate

15. ………… is the common name for acetic acid.
Answer: Ethanoic acid

16. ………… gas burns with a pop sound.
Answer: Hydrogen

17. The process of mixing a non-metal or metal to a molten metal is called …………
Answer: Alloy

III. True Or False

1. Rust is different from iron on which it gets deposited.
Answer: True

2. Burning of a substance is a physical change.
Answer: False

3. Magnesium hydroxide solution turns blue litmus red.
Answer: False

4. Blue colour of copper sulphate solution changes to green when iron nail is dipped in it.
Answer: True

5. Reaction of magnesium with oxygen gives magnesium hydroxide.
Answer: False

6. Vinegar and baking soda when mixed together produce carbon dioxide, lime water milky
Answer: True

7. Hydrogen gas is produced when acetic acid reacts with sodium hydrogen carbonate.
Answer: False

8. When magnesium is burnt in air, magnesium oxide is formed.
Answer: True

9. Copper burns with a dazzling white flame.
Answer: False

10. Hydrogen gas turns lime water milky.
Answer: False

11. Most of the chemical changes are reversible.
Answer: False

12. Crystallisation is a reversible, physical change.
Answer: False

Class 7 Science MCQ