Reasonance and Hybridization

Question 1

Carbon-carbon double bonds consist of:

a) one σ bond, one π bond
b) two σ bond, one π bond
c) one σ bond, two π bonds
d) two σ bonds, two π bonds

Answer 1

a) one σ bond, one π bond

Question 2

When the carbon is sp2 hybridized in a compound, it is bonded to:

a) 2 other atoms
b) 3 other atoms
c) 4 other atoms
d) 5 other atoms

Answer 2

b) 3 other atoms

Question 3

What is the bond angle between the hybrid orbitals in methane?

a) 180 degrees
b) 120 degrees
c) 109.5 degrees
d) 115.5 degrees

Answer 3

109.5 degrees

Question 4

the H-C-H bond in ethane angle is

a) 60
b) 120
c) 90
d) 180

Answer 4

b) 120

Question 5

The phenomenon of forming completely new atomic orbitals by intermixing them is known as?

Answer 5

hybridization

Question 6

In propene there are
a) 8 σ and 1 π
b) 7 σ and 2 π
c) 6 σ and 3 π
d) 9σ

Answer 6

a) 8 σ bonds and 1 π

Question 7

What is the relationship between 1-butene and cis-2-butene?

a) unrelated compounds
b) constitutional isomers
c) enantiomers
d) diastereomer

Answer 7

b) constitutional isomers

Question 8

Which of the following molecules exist as a pair of enantiomers?

a) 2-bromopropane
b) 1-bromo-3-methylbutane
c) 2-cyclohexene-1-ol
d) cis-1,2-dichlorocyclobutane

enantiomers are optical isomers

Answer 8

c) 2-cyclohexene-1-ol

Question 9

Name this compound

Cl CH3
| |
CH3CHC=CHCH3

a) 2-chloro-3-methylpent-3-ene
b) 4-chloro-3-methylpent-2-ene
c) 3-methyl-4-chloropent-2-ene
d) 3-methyl-2-chloropent-3-ene

Answer 9

b) 4-chloro-3-methylpent-2-ene

The double has priority over the side groups

Question 10

What atomic orbitals are invovled in making a C-H bond in methane?

a) A 2p orbital on C and a 1s orbital on H
b) a 2s orbital on C and a 1s orbital on H
c) An sp3 orbital on C and a 1s orbital on H
d) An sp2 orbital on C and a 1s orbital on H

Answer 10

c) An sp3 orbital on C and a 1s orbital on H

Question 11

What is the bond angle of H-C-H in methane molecule?

a) 104.5
b) 109.5
c) 108
d) 120

Answer 11

b) 109.5

Question 12

How many sigma bonds are in ethene?

a) 6
b) 7
c) 4
d) 5

Answer 12

d) 5

Question 13

True or false?

The orbitals formed after hybridization have equal energy

Answer 13

True

Question 14

Which of the following statements is true regarding hybrid orbitals?

a) The number of orbitals formed after the hybridization is not equal to the number of orbitals before hybridization

b) The hybrid orbitals don’t have equal enegry

c) They can form more stable bonds than the pure orbitals

d) Hybridization doesn’t indicate geometry

Answer 14

c) They can form more stable bonds than the pure orbitals

Question 15

A π bond is the result of the

a) overlap of two s orbitals
b) overlap of an s and a p orbital
c) overlap of two p orbitals along their axes
d) sideways overlap of two parallel p orbitals

Answer 15

d) sideways overlap of two parallel p orbitals

Question 16

What kind of orbitals are utilized by carbon atomin CF4

a) sp
b) sp2
c) sp3
d) sp3d

Answer 16

c) sp3

Question 17

Which molecule has a linear arrangment of all component atoms?

a) CH4
b) H2O
c) CO2
d) NH3

Answer 17

c) CO2

Question 18

Which of the following is not a priority rule for R, S-configuration?

a) If the four atoms attached to the chiral center are all different, priority depends on atomic number, with the atom of lower atomic numbers getting lower priority

b) If the two atoms attached the chiral center are the same, the atoms attached to each of these first atoms are compared

c) When there is a double or triple bond, both atoms are considered to be duplicated or triplicated.

d) If the four atoms attached to the chiral center are all different, priority depends on atomic number, with the atom of higher atomic numbers getting lower priority

Answer 18

d) If the four atoms attached to the chiral center are all different, priority depends on atomic number, with the atom of higher atomic numbers getting lower priority

Higher atomic numbers lead to a higher priority not lower

Question 19

If our eyes travel in a counter clockwise direction from the ligand of highest priority to the ligand of lowest priority, the configuration is __?

a) R-configuration
b) S-configuration
c) E-configuration
d) Z-configuration

Answer 19

b) S-configuration

Question 20

Which of the following groups has the highest priority?

a) CH3

b) CH2Cl

c) CH2OH

d) CHO

Answer 20

b) CH2Cl

Question 21

The cis-trans nomenclature is not applicable when

a) The different groups attached to the carbon atom of the double bond are same
b) At least one of the groups attached to each of the carbon atoms is same
c) The different groups attached to the carbon atom of the double bond are not same
d) The cis-trans nomenclature is applicable for all compounds

Answer 21

c) The different groups attached to the carbon atom of the double bond are not same

Question 22

The isomers which can be inter converted through rotation around a single bond are:

a) conformers
b) Diasteromers
c) Enantiomers
d) Positional isomers

Answer 22

a) conformers

Question 23

Chiral molecules are thos which are:

a) Shows geometrical isomerism
b) superimposable on their mirror images
c) non-superimposable on their mirror images
d) unstable molecules

Answer 23

c) non-superimposable on their mirror images

Question 24

Compound in which carbons use only sp3 hybridization for bond formation is
a) CH3CH2CH3
b) CH3C=CH
c) CH3CH=CH2
d) CH2=CH–CH=CH2

Answer 24

a) CH3CH2CH3

Question 25

Which statement is true?

a) Resonance hybrids are inherently unstable
b) Resonance hybrids are more stable than any individual resonance form
c) Resonance hybrids are averages of all resonance forms resembling the less stable forms
d) Resonance hybrids are averages of all resonance forms resembling the more stable forms

Answer 25

d) Resonance hybrids are averages of all resonance forms resembling the more stable forms