During the formation of a chemical bond between two atoms:
  • Only forces of repulsion are operative
  • Forces of attraction and repulsion forces, both are operative
  • Forces are not involved
  • Only forces of attraction are operative
Who discovered the octet rule?
  • Langmuir
  • Debye
  • Boyle
  • Kossel and Lewis
The Lewis structure of H2S is: H:S:H H.S.H H:S.H
50102_Structure1.gif
  • A
  • B
  • C
  • D
A CO2 molecule contains:
  • Two sigma and two pi bonds
  • Four sigma bonds
  • Three sigma and one pi bond
  • Four pi bonds
Which one of them is an odd-electron molecule?
  • BCl3
  • SF6
  • NO
  • CO2
According to the Lewis symbols, the nucleus as well as the electrons in the inner shell of an element is represented by:
  • The symbol of the element
  • The number of dots on the symbol
  • Atomic mass
  • Atomic number
For the formation of covalent bond the difference in the value of electro negativities should be:
  • Less than 2.7
  • Equal to 2.7
  • More than 1.7
  • Equal to or less than 1.7
Select the molecule in which the central atom has incomplete octet.
  • NF3
  • BeH2
  • H2O
  • CO2
Among the following compounds octet rule is not obeyed by:
  • PCl3
  • SF6
  • SO3
  • SO2
The correct Lewis dot structure for BeF2 molecule is: F.Be.F  F: Be: F F.Be: F
6927_image001.gif
  • A
  • B
  • C
  • D
The number of dots in the Lewis symbol represents:
  • The number of valence electrons present in the atom
  • Atomic mass of the element
  • Atomic number of the element
  • The electronic configuration of the atom
According to Lewis symbol, the valency of N is:
  • 4
  • 3
  • 2
  • 6
The formal charge on oxygen which is single bonded in ozone is:
  • -1
  • +1
  • +2
  • -2
The formation of a chemical bond is accompanied by:
  • Sometimes increase and sometimes decrease in energy
  • Decrease in energy
  • Increase in energy
  • Neither increase nor decrease in energy
Identify an example of covalent solid:
  • Sodium chloride
  • Silicon carbide
  • Calcium chloride
  • Methane
Covalent compounds are soluble in:
  • Polar solvents
  • Non-polar solvents
  • Concentrated acids
  • All solvents
A force which binds atoms of same or different elements by mutual sharing of electrons is called:
  • Covalent bond
  • Co-ordinate bond
  • Hydrogen bond
  • Ionic bond
Which one of the following statement is not true for octet rule?
  • It does not explain relative stability of molecules.
  • It is useful for understanding structures of most of organic compounds.
  • It is based upon the chemical inertness of noble gases.
  • It accounts for the shape of molecules.
Among the following molecules octet rule is not obeyed by:
  • OF2
  • CO2
  • PCl3
  • ClF3
The number of electrons present in the valence shell of the central atom of super octet molecules is:
  • Six
  • More than eight
  • Eight
  • Two
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