Question

Answer the Match the column in the attachment

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Multiple Choice Questions :-

1. A Chemical change

(a) does not form new substances
(b) is mostly reversible, sometimes irreversible
(c) forms new substances
(d) is always irreversible

2. Melting of wax is

(a) Reversible physical change
(b) Irreversible physical change
(c) Reversible chemical change
(d) Irreversible chemical change

3. Common salt produced by from sea water by

(a) Evaporation
(b) Crystallization
(c) Both (a) and (b)
(d) None of the above

4. Zn + H₂SO₄ → ZnSO₄ + H₂

This is a _____________ type of reaction

(a) Combination
(b) Displacement
(c) Double displacement
(d) Neutralisation


5. Which one is Metal?

(a) Silicon
(b) Iodine
(c) Oxygen
(d) Zinc

6. Ozone (0₃) molecule is

(a) Triatomic
(b) Monoatomic
(c) Diatomic
(d) Atom

7. Reddish brown compound form on iron on exposure to moist air is

(a) oxygen
(b) water and oxygen
(c) rust
(d) none of the above

8. Liquid metal is

(a) lodine
(b) Water
(c) Mercury
(d) Iron

9. Only non-metal that is a good conductor of electricity is

(a) Diamond
(b) Graphite
(c) Iodine
(d) Bromine

10. Calcium carbonate has formula

(a) NaHCO₃
(b) CaO
(c) CaCO₃
(d) CaCO₂

11. A molecule of a compound has the formula X₂0₃. How many atoms are there in its molecule?

(a) 7
(b) 5
(c) 2
(d) 1​

Answer 1

Required Answer:-

Match the columns:

1. Exothermic reaction - Energy evolved
2. Endothermic reaction - Energy absorbed
3. Oxidation - Gain of oxygen
4. Reduction - Loss of oxygen
5. Mixture - Sea water
6. Compound - CO2
7. H2SO4 - Chemical formulae
8. Salt - Sea water
9. Burning of fuels - Petroleum
10. Iron - Rust

_________________

Multiple choice questions$:$

1) A Chemical change:

• form new substances (C)

2) Melting of wax is:

• Reversible physical change (A)

3) Common salt produced by from sea water by:

• Both A and B, Evaporation and then crystallization. (C)

4) Zn + H₂SO₄ → ZnSO₄ + H₂

• This is a displacement type of reaction (B)

5) Which one is Metal?

• Zinc (D)

6) Ozone (0₃) molecule is:

• Triatomic (A)

7) Reddish brown compound form on iron on exposure to moist air is:

• Rust (C)

8) Liquid metal is:

• Mercury (C)

9) Only non-metal that is a good conductor of electricity is:

• Graphite (B)

10) Calcium carbonate has formula:

• CaCO3 (C)

11) A molecule of a compound has the formula X₂0₃. How many atoms are there in its molecule?

• 2 + 3 = 5 (B)

Answer 2

Match The Following.

1. Exothermic reaction = Energy evolved
2. Endothermic reaction = Energy absorbed
3. Oxidation = Gain of oxygen
4. Reduction = Loss of oxygen
5. Mixture = Sea water
6. Compound = CO2
7. H2SO4 = Chemical formulae
8. Salt = Sea water
9. Burning of fuels. = Petroleum
10. Iron = Rust

Multiple choice questions:

1) C

Chemical change forms new substances.

2) A

Melting of wax is a Reversible physical change.

3) C

Common salt can be produced from sea water by Evaporation and crystallization.

4) B

Zn + H₂SO₄ ———→ ZnSO₄ + H₂

This is a displacement type of reaction

5) D

Zinc is a metal.

6) A

Ozone is a triatomic molecule.

7) C

Reddish brown compound form on iron on exposure to moist air is Rust.

8) C

Mercury is a liquid Metal.

9) B

Graphite is the Only non-metal that is a good conductor of electricity.

10) C

CaCO3 is the formula of Calcium Carbonate.