Properties of alkanes

Question 1

Define saturated

Answer 1

containing single C-C bonds

Question 2

Define tetrahedral

Answer 2

each carbon atom has 4 pairs of bonding electrons around it

Question 3

What is the bond angle of a tetrahedral molecule?

Answer 3

109.5

Question 4

What is the general formula of an alkane?

Answer 4

CnH2n+2

Question 5

What forces are there between molecules?

Answer 5

London forces ( induced dipole-dipole interactions)

Question 6

When the carbon chain gets longer, what happens to the London forces and why?

Answer 6

London forces get stronger because there’s more surface contact and more electrons to interact

Question 7

What happens to the boiling point as molecules get longer?

Answer 7

it takes more energy to overcome the London forces so the boiling point rises

Question 8

Do branched-chain alkanes have lower or higher boiling points than its straight-chain isomer & why?

Answer 8

lower boiling point because branched-chain alkanes can’t pack closely together and they have smaller molecular surface areas- so London forces are reduced