CLASS 10

CHAPTER - 1 [MCQ]

1. You are given the following chemical reaction: This reaction represents

A) Combination reaction as well as double displacement reaction
B) Redox reaction as well as displacement reaction
C) Double displacement reaction as well as redox reaction
D) Decomposition reaction as well as displacement reaction

... Answer is B)
This reaction represents is "Redox reaction as well as displacement reaction"

2. Rusting of iron involves a chemical reaction which is a combination of?

A) Reduction as well as combination reactions
B) Oxidation as well as combination reactions
C) Reduction as well as displacement reactions
D) Oxidation as well as displacement reactions

... Answer is B)
Rusting of iron involves a chemical reaction which is a combination of"Oxidation as well as combination reactions".

3. When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:

A) Blue to green
B) Green to blue
C) Green to brown
D) Green to yellow

... Answer is C)
. The change in colour "Green to brown".

4. The displacement reaction between iron (III) oxide and a metal X is used for welding the rail tracks. Here X is:

A) Copper granules
B) Magnesium ribbon
C) Sodium pellets
D) Aluminium dust

... Answer is D)
This is an Aluminium dust.

5. A substance added to food containing fats and oils is called

A) Oxidant
B) Rancid
C) Coolant
D) Antioxidant

... Answer is D)
The substance is an Antioxidant.

6. In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?

A) Lead sulphate
B) Lead acetate
C) Ammonium nitrate
D) Potassium sulphate

... Answer is B)
Lead acetate.

7. Which of the following are exothermic processes? (i) Reaction of water with quick lime (ii) Dilution of an acid (iii) Evaporation of water (iv) Sublimation of camphor (crystals)

A) (i) and (ii)
B) (ii) and (iii
C) (i) and (iv
D) (ii) and (iv)

... Answer is A)
exothermic processes are(i) Reaction of water with quick lime (ii) Dilution of an acid.

8. Which among the following statement(s) is (are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to (i) the formation of silver by decomposition of silver chloride (ii) sublimation of silver chloride (iii decomposition of chlorine gas from silver chloride (iv) oxidation of silver chloride

A) (i) only
B) (i) and (iii)
C) (ii) and (iii)
D) (iv) only

... Answer is A)
Exposure of silver chloride to sunlight for a long duration turns grey due tothe formation of silver" by decomposition of silver chloride".

9. When Ag is exposed to air it gets a black coating of?

A) AgNO3
B) Ag2S
C) Ag2O
D) Ag2CO3

... Answer is B)
When Ag is exposed to air it gets a black coating of" due to formation of Ag2S".

10. When S02 gas is passed through saturated solution of H2S, which of the following reaction occurs?

A) SO2 + 2H2S → 2H20 + 3S
B) SO2 + 2H2S → H20 + 3S
C) SO2 + H2S → H2O + S
D) SO2 + H2O → SO3 + H2

... Answer is A)
The oxidation state changefrom +4 to 0 and -2 to 0 "SO2 + 2H2S → 2H20 + 3S".