Unit 1 Structure and Bonding

Question 1

Pure covalent bond

Answer 1

Equal sharing of a pair of e between two nuclei (Same electronegativity)

Question 2

Permanent dipole

Answer 2

In HF F has a higher electronegativity so the dipole is pulled towards it

F becomes slightly negative δ−
H becomes slightly positive δ+

Question 3

Bonding continium

Answer 3

​≤0.4: pure covalent >0.4:Polar >1.7:ionic
(Non polar)

Question 4

When do dipoles cancel out

Answer 4

Linear and Sometimes Tetrahedral

Question 5

How are LDF’s formed

Answer 5

Formed by electrostatic attraction between temporary and induced dipoles

Question 6

How are the dipoles formed

Answer 6

Electron cloud wobbles causing a temporary dipole which can induce a dipole by distorting it electron cloud

Question 7

PD-PDI

Answer 7

Only occurs between polar molecules
Opposite charged ends attracting

Question 8

Hydrogen bonding

Answer 8

Strongest IMF
Hydrogen can bond to F, O & N

Question 9

When is it fair to compare 2 molecules

Answer 9

Same or similar number of electrons/mass
Same IMF’s

Question 10

Ionic bonding

Answer 10

Between metals and non-metals
Metals lose electrons to become positively charged ions, whilst non-metals gain to become negatively charged ions

Question 11

Covalent bonding

Answer 11

Between non-metal atoms