7) Unit 2 - Molecular Orbitals

Question 1

What is produced when two atomic orbitals approach each other

Answer 1

2 Molecular orbitals:
•bonding/molecular orbital
•anti-bonding orbital

Question 2

why do electrons tend to be in the molecular orbitals

Answer 2

they are of lower energy and electrons fill in order of increasing energy

Question 3

describe the molecular orbital

Answer 3

Low energy

Forms the traditional covalent bond, which is the attraction of positive nuclei to negative electron

Question 4

describe the anti-bonding orbital

Answer 4

Higher energy

Question 5

what is hybridisation

Answer 5

the process of mixing atomic orbitals to generate a new set of hybrid orbitals

Question 6

why is hybridisation important in carbon

Answer 6

Carbon 1S2, 2s2, 2p2

This would mean carbon can only make two bonds - but it makes 4.

Question 7

what is an sp3 orbital and where is it found

Answer 7

hybrid orbital made from one s orbital and three p orbital - Found in alkanes as only makes single bonds

Question 8

what is an sp2 orbital and where is it found

Answer 8

hybrid orbital made from one s orbital and two p orbital - there is an extra p orbital left

Found in alkenes because it makes double bonds

Question 9

what is an sp orbital and where is it found

Answer 9

hybrid orbital made from one s orbital and one p orbital - there are 2 extra p orbitals left

found in alkynes as it makes 3 bonds (triple)

Question 10

how many sigma and pi bonds are in a:

single bond

Answer 10

1 sigma

0 pi

Question 11

how many sigma and pi bonds are in a:

double bond

Answer 11

1 sigma

1 pi

Question 12

how many sigma and pi bonds are in a:

triple bond

Answer 12

1 sigma

2 pi

Question 13

how can a sigma bond be formed

Answer 13

s + s 'end on'
s + p 'end on'
p + p 'end on'
sp + sp 'end on'
sp + s 'end on'

Question 14

how can a pi bond be formed

Answer 14

p + p ‘side on’

Question 15

which is weaker, side on or end on

Answer 15

side on

Question 16

what kind of molecular orbital is present in in pure covalent/ non polar bonds

Answer 16

symmetrical - molecular orbital is equally shared over both nuclei because of very similar electronegativity

Question 17

what kind of molecular orbital is present in in pure covalent/ non polar bonds

Answer 17

asymmetrical - molecular orbital is assymetrical as electrons are pulled more to the side with higher electronegativity

Question 18

what kind of molecular orbital is present in in ionic bonds

Answer 18

Molecular orbital is extremely asymmetrical with the molecular orbital being located around one atom in the bond