Structure of Molecule

9th chemistry chapter 4 solved exercise MCQs

1. Atoms react with each other because :

(a) they are attracted to each other

(b) they are short of electrons

(c) they want to attain stability  ✔

(d) they want to disperse

2. An atom having six electrons in its valence shell will achieve noble gas electronic configuration by :

(a) gaining two electrons

(b) losing all electrons

(c) gaining two electrons  ✔

(d) losing two electrons

3. Considering the electronic configuration of atoms which atom with the given atomic number will be the most stable one ?

(a) 6

(b) 8

(c) 10  ✔

(d) 12

4. Octet rule is :

(a) description of eight electrons

(b) picture of electronic configuration

(c) pattern of electronic configuration

(d) attaining of eight electrons  ✔

5. Transfer of electrons between atoms results in :

(a) metallic bonding

(b) ionic bonding  ✔

(c) covalent bonding

(d) coordinate covalent bonding

6. When an electronegative element combines with an electropositive element the type of bonding is :

(a) covalent

(b) ionic  ✔

(c) polar covalent

(d) coordinate covalent

7. A bond formed between two non-metals is expected to be :

(a) covalent  ✔

(b) ionic

(c) coordinate covalent

(d) metallic

8. A bond pair in covalent molecules usually has :

(a) one electron

(b) two electrons  ✔

(c) three electrons

(d) four electrons

9. Which of the following compounds is not directional in its bonding ?

(a) CH4

(b) KBr  ✔

(c) CO2

(d) H2O

10. Ice floats on water because :

(a) ice is denser than water

(b) ice is crystalline in nature

(c) water is denser than ice  ✔

(d) water molecules move randomly

11. Covalent bond involves the :

(a) donation of electrons

(b) acceptance of electrons

(c) sharing of electrons  ✔

(d) repulsion of electrons

12. How many covalent bonds does C2H4 molecule have ?

(a) two

(b) three

(c) four

(d) five  ✔

13. How many electrons does a triple covalent bond involve?

(a) eight

(b) six  ✔

(c) four

(d) only three

14. Which pair of molecules has same type of covalent bonds ?

(a) O2 and HCl

(b) O2 and N2

(c) O2 and C2H4  ✔

(d) O2 and C2H2

15. Identify the compound which is not soluble in water .

(a) C6H6

(b) NaCl

(c) KBr

(d) MgCl2

16. Which one of the following is an electron deficient molecule ?

(a) NH3

(b) BF3  ✔

(c) N2

(d) O2

17. Identify which pair has polar covalent bonds .

(a) O2 and Cl2

(b) H2O and N2

(c) H2O and C2H2

(d) H2O and HCl  ✔

18. Which one of the following is the weakest force among the atoms ?

(a) ionic force

(b) metallic force

(c) intermolecular force  ✔

(d) covalent force