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Chemistry Class 9 Chapter 4


Updated: 01 Oct 2023

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Chemistry Class 9 Chapter 4 is about the “Structure of Molecules.” This article includes topics such as Chemical Bonding, Types of Bonds, Ionic Bond, Covalent Bond, Types of Covalent Bond, Co-ordinate Covalent Bond, Polar and Non-Polar Covalent Bond, Metallic Bond, Shapes of Molecules, Intermolecular Forces, Dipole-Dipole Interaction, Hydrogen Bonding, Properties of Ionic, Properties of Covalent and Properties of Metals.

Chemistry Class 9 Chapter 4 Notes

Structure of Molecules

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Chemistry Class 9 Chapter 4 Notes

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Chemistry Class 9 Chapter 4-MCQs

Chemical Bond

Types of Bonds

1. The attractive force which keeps the atom _______ in a substance is called bond.
(a) Together
(b) Separate
(c) In shift
Show Answer

Together


2. All elements and compounds are formed by the combination of atoms except the _______
(a) Hydrocarbon
(b) Noble gases
(c) Isotopes
Show Answer

Noble gases


3. ________ combine with one another by chemical process is called chemical bonding.
(a) Atoms
(b) Elements
(c) Compounds
Show Answer

Atoms


4. Every system in universe tends to lower its energy to attain ________
(a) Reactivity
(b) Molarity
(c) Stability
Show Answer

Stability


5. Atoms also have the tendency to ________ their energy.
(a) Increase
(b) Decrease
(c) Unchanged
Show Answer

Decrease


6. The combination of atoms gives stable molecule through emission of ________
(a) Energy
(b) Gases
(c) Particles
Show Answer

Energy


7. In 1916 , G.N Lewis and _____proposed the electronic theory of valance .
(a) Max plank
(b) W.Kossel
(c) Schrodinger
Show Answer

W.Kossel


8. The valance concept states that, in a chemical bond formation , atoms take part by losing , gaining or sharing of electrons to attain noble gas _______
(a) Stability
(b) Reactivity
(c) Electronic configuration
Show Answer

Electronic configuration


9. When atoms have two or eight electrons in their valance shell , they are ______
(a) Stable
(b) Reactive
(c) Unstable
(d) Non-reactive
Show Answer

Stable


10. The tendency of atom to attain ______ electrons in valance shell to attain stability is called octet theory .
(a) Eight
(b) Two
(c) Ten
Show Answer

Eight


11. By gaining two electrons from other atom, oxygen will complete its _____ and become stable.
(a) Duplet
(b) Triplet
(c) Octet
Show Answer

Octet


12. The tendency of atom to attain _______ electrons in its valence shell to attain stability is called duplet theory .
(a) Eight
(b) Two
(c) Ten
Show Answer

Two


13. ____ has two electrons in its valence shell and it is stable.
(a) Helium
(b) Lithium
(c) Thorium
Show Answer

Helium


14. Elements of Group-VIII are called ____ gases .
(a) Alkali
(b) Noble
(c) Halogens
Show Answer

Noble


15. Elements of Group-VIII are very stable and ______ take part in chemical reaction to form compounds.
(a) Commonly
(b) Every time
(c) Rarely
Show Answer

Rarely


16. The orbital concept is based on combination of atomic ______ to produce molecular orbital.
(a) Orbital
(b) Shells
(c) Ions
Show Answer

Orbital


17. The atomic orbitals have only ______ electron.
(a) 3
(b) 1
(c) 2
(d) 4
Show Answer

1


18. Endwise overlapping produce _____ bond.
(a) Pi
(b) Ionic
(c) Sigma
(d) None of these
Show Answer

Sigma


19. Sidewise overlapping produce _______ bond.
(a) Pi
(b) Ionic
(c) Sigma
(d) None of these
Show Answer

Pi


20. The attractive force which hold the atom together to form a molecule is called _______
(a) Overlapping
(b) Turbidity
(c) Bond
(d) None of these
Show Answer

Bond


21. There are the ______ main types of bond .
(a) 3
(b) 4
(c) 5
(d) 6
Show Answer

4


Ionic Bond

22. The chemical bond which is formed due to the ________ transfer of electron from one atom to another is called ionic bond.
(a) Complete
(b) Partial
(c) Sharing
(d) None of these
Show Answer

Complete


23. Ionic bond is also called _____ bond.
(a) Dative
(b) Polar
(c) Electrovalent
(d) None of these
Show Answer

Electrovalent


24. The transfer of _____ between atoms complete the octets and duplets.
(a) Protons
(b) Electrons
(c) Neutrons
(d) None of these
Show Answer

Electrons


25. Metals always ____ electron to form cations.
(a) Lose
(b) Gain
(c) Share
(d) None of these
Show Answer

Lose


26. Non-metals always ____ electron to form anions
(a) Lose
(b) Gain
(c) Share
(d) None of these
Show Answer

Gain


27. In _______ bond formation, one atom lose electron and the other gains it .
(a) Covalent
(b) Metallic
(c) Ionic
(d) None of these
Show Answer

Ionic


28. The atom that loses an electron acquires _____ charge .
(a) Positive
(b) Negative
(c) Neutral
(d) None of these
Show Answer

Positive


29. The atom that gains electron acquires ____ charge .
(a) Positive
(b) Negative
(c) Neutral
(d) None of these
Show Answer

Negative


30. Due to opposite charges, the ____ force of attraction is set up between the two ions which hold them together.
(a) Electrostatic
(b) Magnetic
(c) London dispersion
(d) None of these
Show Answer

Electrostatic


31. The example of ionic bond is :
(a) H_2
(b) F_2
(c) Cl_2
(d) NaCl
Show Answer

NaCl


Covalent Bond

Types of Covalent Bond

32. A bond formed when two atoms joined together by _____ of electrons is called covalent bond.
(a) Gaining
(b) Sharing
(c) Losing
(d) None of these
Show Answer

Sharing


33. Covalent bonds are formed between two _____ elements .
(a) Non-metallic
(b) Metallic
(c) Flammable
(d) None of these
Show Answer

Non-metallic


34. Lewis proposed that two atoms attain _____ electronic configuration by sharing electrons between them.
(a) Unstable
(b) Stable
(c) Unreactive
(d) None of these
Show Answer

Stable


35. The shared pair of electrons between two bonded atoms are called ______ electrons.
(a) Localized
(b) Delocalized
(c) Shared
(d) None of these
Show Answer

Localized


36. All are the examples of covalent bond EXCEPT
(a) HCl
(b) NaCl
(c) H_2
(d) O_2
Show Answer

NaCl


37. The bond in which two atoms share ______ electron each to form a pair of electron is called single covalent bond
(a) One
(b) Two
(c) Three
(d) Four
Show Answer

One


38. A single straight line ______ shows single covalent bond.
(a) -
(b) =
(c)
(d) None of these
Show Answer

-


39. ____ is the example of single covalent bond .
(a) NaCl
(b) CH_4
(c) O_2
(d) None of these
Show Answer

CH_4


40 The bond in which two atoms share ________ electrons is each to form two pair of electrons called double covalent bond
(a) Single
(b) Two
(c) Three
(d) None of these
Show Answer

Two


41. A double straight line________ shows double covalent bond .
(a) -
(b) =
(c)
(d) None of these
Show Answer

=


42. All are the example of double covalent bond EXCEPT :
(a) O_2
(b) C_2H_4
(c) CO_2
(d) F_2
Show Answer

F_2


43. The bond in which two atoms share_______ electrons to form three pairs of electrons is called triple covalent bond
(a) One
(b) Two
(c) Three
(d) None of these
Show Answer

Three


44. A triple straight line shows a covalent bond in which total of _____ electrons are shared.
(a) 3
(b) 6
(c) 9
(d) 12
Show Answer

6


45. The example of triple covalent bond is :
(a) N_2
(b) C_2 H_4
(c) CO_2
(d) None of these
Show Answer

N_2


46. The atomic number of Nitrogen is ________
(a) 9
(b) 7
(c) 5
(d) 3
Show Answer

7


47. Nitrogen has five ____ in its valence shell
(a) Neutron
(b) Protons
(c) Electron
(d) None of these
Show Answer

Electron


Co-Ordinate Covalent Bond or Dative Bond

48. The covalent bond in which only one atom donate the _______ of electron is called coordinate covalent bond .
(a) Shared pair
(b) Lone pair
(c) Bond pair
(d) None of these
Show Answer

Shared pair


49. Coordinate covalent bond is also called _____ bond.
(a) Electrovalent
(b) Dative
(c) Polar
(d) None of these
Show Answer

Dative


50. The atom which donate the shared pair of electron is called ______
(a) Donor
(b) Accepter
(c) giver
(d) None of these
Show Answer

Donor


51. The atom which accept the shared pair of electron is called _______
(a) Donor
(b) Accepter
(c) Gainer
(d) None of these
Show Answer

Accepter


52. Which arrow represents coordinate covalent bond ?
(a)
(b) =
(c)
(d)
Show Answer


53. The example of coordinate covalent bond is
(a) NH_4
(b) CH_3
(c) C_2H_2
(d) CO_2
Show Answer

NH_4


To Download Complete Notes of Class 9 Chemistry Notes, Click the link.

Non-Polar Covalent Bond

54. The covalent bond formed by mutual sharing of electrons between atoms, having similar ____ is called non-polar covalent bond.
(a) Electron affinity
(b) Electronegativity
(c) Hybridization
(d) None of these
Show Answer

Electronegativity


55. All are the example of non-polar covalent bond except :
(a) HCl
(b) H_2
(c) Br_2
(d) Cl_2
Show Answer

HCl


Polar Covalent Bond

56. The covalent bond formed by mutual _____ if electrons between atoms , having different electro negativities is called polar covalent bond
(a) Gaining
(b) Losing
(c) Sharing
(d) None of these
Show Answer

Sharing


57. Following are the examples of polar covalent bond except :
(a) H_2
(b) HCl
(c) H_2O
(d) NH_3
Show Answer

H_2


Metallic Bond

58. The metals are formed formed from ____
(a) Elements
(b) Compounds
(c) Molecule
(d) Atoms
Show Answer

Atoms


59. The atoms in metallic solids are bonded _____ to each other.
(a) Loosely
(b) Tightly
(c) Partially
(d) None
Show Answer

Tightly


60 The chemical bonding that result from the attraction between metal positive ions and the surrounding sea of electrons is called _______ bonding
(a) Metallic
(b) Ionic
(c) Covalent
(d) Dative
Show Answer

Metallic


61 Atoms in metals are bonded with each other in such a way that every atom is attracted from _____ by other atom
(a) Two sides
(b) Back and forth
(c) All sides
(d) None of these
Show Answer

All sides


Shapes of Molecules

62. Molecules are extremely _____ in size.
(a) Large
(b) Small
(c) Intermediate
(d) None of these
Show Answer

Small


63. Scientists proved with the experiments that _____ of molecules are linear, triangular, tetrahedral and pyramidal etc
(a) Shapes
(b) Properties
(c) Applications
(d) None of these
Show Answer

Shapes


64. The molecular shape of CO_2 is ____
(a) Trigonal planner
(b) Angular
(c) Linear
(d) None of these
Show Answer

Linear


65. The molecular shape of H_2O is _____
(a) Trigonal planner
(b) Angular
(c) Linear
(d) None of these
Show Answer

Angular


66. The molecular shape of NH_3 is ______
(a) Trigonal pyramidal
(b) Triangular
(c) Tetrahedral
(d) None of these
Show Answer

Trigonal pyramidal


67. The angle inn linear shape of CO_2 molecule is :
(a) 104.5^0
(b) 180^0
(c) 109.5^0
(d) None of these
Show Answer

180^0


Intermolecular Forces

68. The force of attraction between _____ of a compound is called intermolecular force.
(a) molecules
(b) Atoms
(c) Elements
(d) None
Show Answer

molecules


69. The angle in bent shape of H2O molecule is :
(a) 104.5^0
(b) 180^0
(c) 109.5^0
(d) None of these
Show Answer

104.5^0


70. Intermolecular force are ______ times weaker than covalent bond.
(a) 15
(b) 25
(c) 30
(d) 20
Show Answer

25


71. The intermolecular force are of three types collectively called as _____ force
(a) Sub-atomic particle
(b) Van der waals
(c) Sedimentation
(d) None of these
Show Answer

Van der waals


Dipole-Dipole Interaction

72. The attractive forces between positive pole of one polar molecule and negative pole of other polar molecule are called _______ interaction
(a) Dipole – dipole
(b) London dispersion
(c) Hydrogen bonding
(d) None of these
Show Answer

Dipole – dipole


73. Polar covalent molecules are described as _______
(a) Diatomic
(b) Dipoles
(c) Polyatomic
(d) None of these
Show Answer

Dipoles


74. All are the examples of dipole-dipole interaction except:
(a) CO
(b) HCl
(c) H_2S
(d) Hg
Show Answer

Hg


75. To break the dipole-dipole interaction in HCl molecules , it requires _____ energy
(a) 3.3 kj /mol
(b) 3.3 A^0
(c) 3.3 Hz
(d) 3.3 joules
Show Answer

3.3 kj /mol


76. Hydrogen chloride (HCl) boils at ________
(a) 85^0 C
(b) -85^0 C
(c) 100^0 C
(d) 63^0 C
Show Answer

-85^0 C


Hydrogen Bonding

77. The attractive force between highly electron deficient hydrogen atom and nearby highly electronegative atom with lone pair of electrons is called_______
(a) Dipole-dipole
(b) Hydrogen bonding
(c) None
Show Answer

Hydrogen bonding


78. Hydrogen bond is _____ than dipole–dipole forces.
(a) Stronger
(b) Same
(c) Weaker
(d) None of these
Show Answer

Stronger


79. Hydrogen bond is ___________ than covalent bond.
(a) Stronger
(b) Same
(c) Weaker
(d) None of these
Show Answer

Weaker


80. Hydrogen bond is _____ times weaker than covalent bond
(a) 15
(b) 20
(c) 25
(d) 30
Show Answer

20


81. Hydrogen bond is _______ time stronger than dipole-dipole interaction
(a) 10
(b) 12
(c) 14
(d) 15
Show Answer

10


82. Hydrogen bond is _______
(a) Non-directional
(b) Directional
(c) Both
(d) None
Show Answer

Directional


Properties of Ionic Compounds

83. Ionic compound are _____ at room temperature .
(a) Gas
(b) Liquid
(c) Solid
(d) Plasma
Show Answer

Solid


84. Ionic compounds have sharp _____ points
(a) Melting
(b) Boiling
(c) Freezing
(d) Both a and b
Show Answer

Both a and b


85. Ionic compounds are ____ in polar solvents like water.
(a) Soluble
(b) Insoluble
(c) Semi – soluble
(d) None of these
Show Answer

Soluble


86. Ionic compounds are ______ in molten or solution form.
(a) Strong electrolytes
(b) Weak electrolytes
(c) Non-electrolytes
(d) None of these
Show Answer

Strong electrolytes


Properties of Covalent Compounds

87. Covalent compounds have ______ melting and boiling points .
(a) High
(b) Constant
(c) Low
(d) None of these
Show Answer

Low


88. Covalent compounds are ______ in solution form.
(a) Strong electrolyte
(b) Non – electrolytes
(c) Weak electrolytes
(d) None of these
Show Answer

Non – electrolytes


89. The bond in ________ compounds are directional .
(a) Covalent
(b) Ionic
(c) Metallic
(d) None of these
Show Answer

Covalent


90. Covalent compounds depends upon
(a) Geometry
(b) Polarity
(c) Bond types
(d) All of them
Show Answer

All of them


Properties of Metals

91. All metal are solid at room temperature and pressure EXCEPT :
(a) Gold
(b) Mercury
(c) Aluminums
(d) None of these
Show Answer

Mercury


92. The property of metals in which they can beaten into sheets and foils are called _____
(a) Malleability
(b) Ductility
(c) Lustrous
(d) None of these
Show Answer

Malleability


93. Metals are __________ they can be drawn into wires.
(a) Covalent
(b) Ductile
(c) Ionic
(d) Non- conduction
Show Answer

Ductile


94. Metal are also ______
(a) Lustrous
(b) Sonorous
(c) Good conductor
(d) All of them
Show Answer

All of them


Review Exercise Chapter 4

1. An atom with a charge is called :
(a) An electron
(b) A molecule
(c) A metal
(d) An ion
Show Answer

An ion


2. An elements X is in group VI of the periodic table. The ion will be represented by :
(a) X^+
(b) X^-
(c) X^{-2}
(d) X^{+2}
Show Answer

X^{-2}


3. Which pair of elements will join to form a compound with one to one ratio :
(a) Magnesium and chlorine
(b) Sodium and oxygen
(c) Potassium and fluorine
(d) Lithium and Sulphur
Show Answer

Potassium and fluorine


4. When calcium atom become a calcium ion (Ca^{+2}) :
(a) It loses an electron
(b) It loses two electron
(c) It gains electron
(d) Gain two electrons
Show Answer

It loses two electron


5. Which two elements will form a covalent compounds :
(a) Sodium and oxygen
(b) Copper and oxygen
(c) Carbon and Oxygen
(d) Magnesium and Oxygen
Show Answer

Magnesium and Oxygen


6. In the formation of ionic bond, the atoms taking part :
(a) Only gain electrons
(b) Share electrons
(c) Lose and gain of electron
(d) Only lose electrons
Show Answer

Lose and gain of electron


7. Fluorine has an electronic configuration 2, 7 and Oxygen 2, 6. The formula of fluorine oxide will be :
(a) FO
(b) F_2O
(c) FO_2
(d) F_2O_2
Show Answer

F_2O


8. Which of these statements about covalent bonds in incorrect :
(a) HCl contain one pair of shared electrons
(b) CCl_4 contain four pairs of shared electrons
(c) H_2O contain three pairs of shared electrons
(d) NH_3 contains three pairs of shared electrons
Show Answer

H_2O contain three pairs of shared electrons


9. Which of the following ions do not have the electronic configuration of an argon atom?
(a) Ca^{+2}
(b) S^{-2}
(c) K^+
(d) O^{-2}
Show Answer

O^{-2}


10. Which one of the groups below contains only ionic compounds?
(a) Calcium oxide, Hydrogen oxide Chlorine, Magnesium oxide
(b) Calcium oxide , magnesium oxide, sodium chloride
(c) Carbon dioxide , Copper sulphate ,Hydrogen Chloride
(d) Copper sulphate, methane , sodium chloride
Show Answer

Calcium oxide , magnesium oxide, sodium chloride


Chemistry Class 9 MCQs (All Chapters)


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