9th class Chemistry, Chapter 3: Chemical Bonding MCQs

1. When molten copper and molten zinc are mixed together, they give rise to a new substance called brass. Predict what type of bond is formed between copper and zinc.

1. (A) Coordinate covalent bond
2. (B) Ionic bond
3. (C) Metallic bond ✓
4. (D) Covalent bond

2. Which element is capable of forming all the three types of bonds; covalent, coordinate covalent and ionic?

1. (A) Carbon
2. (B) Oxygen ✓
3. (C) Magnesium
4. (D) Silicon

3. Why is H₂O a liquid while H₂S is a gas?

1. (A) Because in water, the atomic size of oxygen is smaller than that of sulphur
2. (B) Because water is a polar compound and there exists strong forces of attraction between its molecules ✓
3. (C) Because H₂O molecule is lighter than H₂S
4. (D) Because water can easily freeze into ice

4. Which of the following bonds is expected to be the weakest?

1. (A) C−C
2. (B) Cl−Cl
3. (C) O−O ✓
4. (D) F−F

5. Which form of carbon is used as a lubricant?

1. (A) Coal
2. (B) Diamond
3. (C) Graphite ✓
4. (D) Charcoal

6. Keeping in view the intermolecular forces of attraction, indicate which compound has the highest boiling point.

1. (A) H₂O ✓
2. (B) H₂S
3. (C) HF
4. (D) NH₃

7. Which metal has the lowest melting point?

1. (A) Li
2. (B) Na
3. (C) K
4. (D) Rb ✓

8. Which ionic compound has the highest melting point?

1. (A) NaCl ✓
2. (B) KCl
3. (C) LiCl
4. (D) RbCl

9. Which compound contains both covalent and ionic bonds?

1. (A) MgCl₂
2. (B) NH₄Cl ✓
3. (C) CaO
4. (D) PCl₃

10. Which among the following has a double covalent bond?

1. (A) Ethane
2. (B) Methane
3. (C) Ethylene ✓
4. (D) Acetylene

11. Atoms combine with other atoms because this:

1. (A) Increases their reactivity only
2. (B) Decreases their mass
3. (C) Decreases their energy and increases stability ✓
4. (D) Increases their energy

12. The number of electrons in the outermost shell of helium is:

1. (A) 18
2. (B) 2 ✓
3. (C) 8
4. (D) 1

13. Having eight electrons in the outermost shell to become stable is called the:

1. (A) Hund's rule
2. (B) 2n² rule
3. (C) Octet rule ✓
4. (D) Duplet rule

14. When a hydrogen atom gains one electron it becomes a:

1. (A) Hydride ion (H⁻) ✓
2. (B) Proton (H⁺)
3. (C) Hydrogen molecule (H₂)
4. (D) Deuterium atom

15. For a sodium atom it is easier to:

1. (A) Gain one electron
2. (B) Share seven electrons
3. (C) Lose one electron ✓
4. (D) Gain seven electrons

16. A force of attraction between atoms which holds them together in a molecule or compound is called a:

1. (A) Nuclear force
2. (B) Magnetic force
3. (C) Chemical bond ✓
4. (D) Intermolecular force

17. The arrangement of electrons around the nucleus of an atom in shells and sub-shells is called:

1. (A) Electronic configuration ✓
2. (B) Crystal lattice
3. (C) Isotopic abundance
4. (D) Bond formation

18. The electronic configuration of ₁₇Cl is:

1. (A) 2, 8, 7 ✓
2. (B) 2, 8, 1
3. (C) 2, 7, 8
4. (D) 2, 8, 8

19. An ionic bond is formed by:

1. (A) Donation of an electron pair by one atom
2. (B) A sea of mobile electrons
3. (C) Complete transfer of electrons from one atom to another ✓
4. (D) Mutual sharing of electron pairs

20. Ionic bond is also called:

1. (A) Electrovalent bond ✓
2. (B) Coordinate bond
3. (C) Dative bond
4. (D) Metallic bond