1.3 Basics of Bonding

Question 1

what are covalent bonds a result of

Answer 1

constructively overlapping orbitals

Question 2

what are the two main subdivided types of covalent bonds

Answer 2

sigma and pi bonds

Question 3

what determines the type of covalent bond

Answer 3

how involve overlap the orbitals

Question 4

whaat kind of overlap does sigma bonds have

Answer 4

they have head on overlap between two orbitals

Question 5

what diffrent kinds of orbitals can be combined to produce sigma bonds? do they have to be the same kind? ie.. s and s, p and s?

Answer 5

a sigma bond may arise from any direct overlap between two properly aligned orbitals of the same phase

ie.. constructive bonds

Question 6

what is constructive overlap

Answer 6

when the phase of the two orbitals being combined must be the same form of covalent bond

Question 7

do sigma bond require s orbitals in there bonds

Answer 7

No. For example two properly aligned p orbitals may overlap and form a sigma bond

Question 8

what is the only requirement of sigma bonding

Answer 8

the two portions overlapping combine constructively and in a direct overlap

Question 9

what are pi bonds

Answer 9

they result from indirect (side-on) overlap between two orbitals

Question 10

how do pi bonds compare to sigma bonds

Answer 10

unlike sigma bonds the two orbitals are not able to directly overlap and instead they come close together and slightly bend to constructive overlap

Question 11

in a sigma bond + pi bond a drawing would represent 2 bonds when there is 3 lobes (areas of electron density) why is this

Answer 11

because the pi bond is made from overlap of both lobes on the p orbitals

Question 12

in simple organic systems are pi bonds a result of

Answer 12

they are a result from a indirect overlap of two p orbitals

Question 13

what is the geometric structure of a pi bond

Answer 13

there are two areas one above and one below the nuclei which form the bond

Question 14

how many lobes are in a pi bond

Answer 14

two lobes make up one pi bond

Question 15

what is electronagitivity

Answer 15

the relitive ability of an atom to attract electrons to itself in a chemical compound

Question 16

is the electronegativity of an element a fixed property

Answer 16

no

Question 17

what can electronegativity be influenced by

Answer 17

on its chemical environment because atoms are influenced by the neighbouring atoms in a chemical compound

Question 18

what is the most common values for electronetitivity from

Answer 18

from the pauling scale

Question 19

what is a polar bond

Answer 19

when two atoms with diffrent electronegitivities are covalently bonded together and an unequal sharing of electrons occurs

Question 20

in a polar bond what atom takes the s- symbol

Answer 20

the atom that takes extra electron density (more elecronagitive atom)

Question 21

in a polar bond what atom take the s+ symbol

Answer 21

the atom that gains less electron density (less electronegative)

Question 22

what does the s- and s+ put emphasis on

Answer 22

that there are partial negative and positive charges on those atoms

Question 23

are polar covalent bonds covalent or ionic

Answer 23

they can be thought of as being similar to ionic bonds but where the electrons are still shared between the atoms

Question 24

what are the two ways to indicate if a bond is polar

Answer 24

• the s- and s+
  -the large arrow pointing towards the more electronegative side

Question 25

what do most chemical reactions start with

Answer 25

ionic groups, polar covalent bonds or pi bonds reacting with another molecule

Question 26

what is more reactive pi bonds or sigma bonds

Answer 26

pi bonds are more easly broken and can partake readily in some rxns

Question 27

what bonds are stronger pi or sigma bonds

Answer 27

sigma bonds

Question 28

why are pi bonds weaker

Answer 28

because they involve indirect overlap