CHEM 219 PRINCIPLES OF ORGANIC
CHEMISTRY MODULE 6 PRACTICE EXAM 2026
◉ Urea. Answer: 2KCNO + (NH4)2SO4 --------> 2NH4CNO + K2SO4
,ie, potassium cyanate plus ammonium sulphate when heated forms
ammonium cyanate. NH4CNO -------> NH2CONH2 ,ie, when
ammonium cyanate is heated it forms urea.
◉ Organic chemistry. Answer: It is a branch of chemistry that deals
with the study of carbon and its compounds excluding CO, CO2, CO3
and HCO3. Other than carbon and hydrogen, organic compounds
may contain hetero atoms like nitrogen, oxygen, sulphur,
phosphorus, halogens etc.
◉ Catenation. Answer: The self linking property of an atom to bond
with the same atoms to form a long chain of atoms that may be
branched, unbranched or cyclic is called catenation. It is the self
linking property of an atom to bond with its own atoms through
covalent bonds to form a chain or ring of atoms.
◉ Reason to why carbon forms a large number of compounds.
Answer: Maximum catenation, isomerism, tetra valency
◉ Reason to why carbon can form C-C multiple bonds. Answer:
Strong carbon-carbon bond, tetra valency, small size of carbon atom
,◉ Hybridisation. Answer: The phenomenon of mixing of orbitals of
the same atom having different energies and shape to form equal
number of new orbitals of same energy and shape is called
hybridisation.
◉ Influence of hybridisation. Answer: Hybridisation influences the
shape of the molecules, bond length, bond strength and bond angle.
◉ Types of hybridisation. Answer: Sp3, Sp2 and Sp
◉ Sp3 hybridisation. Answer: 25% of s-character, 75% of p-
character, tetrahedral shape and bond angle of 109 degree 28'.
Example : methane
◉ Sp2 hybridisation. Answer: 33.33% of s-character, 66.66% of p-
character, trigonal planar shape and bond angle of 120 degree.
Example : ethene
◉ Sp hybridisation. Answer: 50% of s-character, 50% of p-character,
linear shape and bond angle of 180 degree. Example : ethyne.
◉ Electronegativity. Answer: It is the capacity of an element to
attract a shared pair of electrons towards itself.
, ◉ Structural representation of organic compounds. Answer: Lewis
electro dot structure, complete structural formula, condensed
structural formula and bond
Line structural formula.
◉ Three dimensional representation of organic molecules. Answer:
Three dimensional representation of organic molecules can be done
using solid dashed wedge formula. Solid wedge is used to indicate a
bond towards the observer while a dashed wedge is used to
represent a bond away from the observer. A straight normal line is
used to represent the bonds present in the plane.
◉ Orbital. Answer: It is the three dimensional region in space where
the probability of finding an electron is maximum. Orbitals maybe of
s, p or d type with shapes -spherical (s), dumbbell(p) or double
dumbbell(d).
◉ Valency. Answer: It is the combining capacity of an atom with
other atoms or its own atoms.
◉ What does valency depend upon and indicate?. Answer: Valency
depends upon the number of electrons present in the valence shell
and it indicates the number of covalent bonds formed by that atom.
CHEMISTRY MODULE 6 PRACTICE EXAM 2026
◉ Urea. Answer: 2KCNO + (NH4)2SO4 --------> 2NH4CNO + K2SO4
,ie, potassium cyanate plus ammonium sulphate when heated forms
ammonium cyanate. NH4CNO -------> NH2CONH2 ,ie, when
ammonium cyanate is heated it forms urea.
◉ Organic chemistry. Answer: It is a branch of chemistry that deals
with the study of carbon and its compounds excluding CO, CO2, CO3
and HCO3. Other than carbon and hydrogen, organic compounds
may contain hetero atoms like nitrogen, oxygen, sulphur,
phosphorus, halogens etc.
◉ Catenation. Answer: The self linking property of an atom to bond
with the same atoms to form a long chain of atoms that may be
branched, unbranched or cyclic is called catenation. It is the self
linking property of an atom to bond with its own atoms through
covalent bonds to form a chain or ring of atoms.
◉ Reason to why carbon forms a large number of compounds.
Answer: Maximum catenation, isomerism, tetra valency
◉ Reason to why carbon can form C-C multiple bonds. Answer:
Strong carbon-carbon bond, tetra valency, small size of carbon atom
,◉ Hybridisation. Answer: The phenomenon of mixing of orbitals of
the same atom having different energies and shape to form equal
number of new orbitals of same energy and shape is called
hybridisation.
◉ Influence of hybridisation. Answer: Hybridisation influences the
shape of the molecules, bond length, bond strength and bond angle.
◉ Types of hybridisation. Answer: Sp3, Sp2 and Sp
◉ Sp3 hybridisation. Answer: 25% of s-character, 75% of p-
character, tetrahedral shape and bond angle of 109 degree 28'.
Example : methane
◉ Sp2 hybridisation. Answer: 33.33% of s-character, 66.66% of p-
character, trigonal planar shape and bond angle of 120 degree.
Example : ethene
◉ Sp hybridisation. Answer: 50% of s-character, 50% of p-character,
linear shape and bond angle of 180 degree. Example : ethyne.
◉ Electronegativity. Answer: It is the capacity of an element to
attract a shared pair of electrons towards itself.
, ◉ Structural representation of organic compounds. Answer: Lewis
electro dot structure, complete structural formula, condensed
structural formula and bond
Line structural formula.
◉ Three dimensional representation of organic molecules. Answer:
Three dimensional representation of organic molecules can be done
using solid dashed wedge formula. Solid wedge is used to indicate a
bond towards the observer while a dashed wedge is used to
represent a bond away from the observer. A straight normal line is
used to represent the bonds present in the plane.
◉ Orbital. Answer: It is the three dimensional region in space where
the probability of finding an electron is maximum. Orbitals maybe of
s, p or d type with shapes -spherical (s), dumbbell(p) or double
dumbbell(d).
◉ Valency. Answer: It is the combining capacity of an atom with
other atoms or its own atoms.
◉ What does valency depend upon and indicate?. Answer: Valency
depends upon the number of electrons present in the valence shell
and it indicates the number of covalent bonds formed by that atom.
