properties of hydrocarbons

what properties depend on the size of the molecule/hydrocarbon?

• viscosity

• flammability

• colour

• cleanliness of burn

how does boiling point change based on size of hydrocarbon?

the bigger the hydrocarbon, higher its boiling point

why do larger hydrocarbons have a higher boiling point?

the size of the intermolecular forces gets stronger and larger with a larger hydrocarbon - so, they require more energy to overcome then

what is viscosity?

ease of flow of a liquid

ex. high viscosity means the liquid is thick and flows less easily

how does viscosity change with hydrocarbon size?

a larger hydrocarbon means that it is more viscous

why does viscosity as molecules increase in size?

increased intermolecular forces of attraction

why are longer chain hydrocarbons bad as fuels?

they are too viscous, and would clog the engines of machines and vehicles

what are longer hydrocarbons more useful for then? why?

useful as lubricants, as they are less likely to burn due to lower flammability and their increased viscosity

how does flammability change with the size of hydrocarbon?

flammability increases with smaller hydrocarbons

why are short chain hydrocarbons so useful?

their flammability makes them useful as fuels, releasing lots of energy