trends in hydrocarbons Flashcards
1
Q
why do alkanes have a low reactivity
A
they have a low polarity
and a high bond enthalpy
2
Q
what 2 reactions of alkanes undergo
A
combustion
reactions with halogens
3
Q
why does ethane have a boiling point of -89 degrees but decane has a boiling point of 174 degrees
A
Decane has a higher relative molecular mass
therefore has a longer chain length as more electrons are present so there are more points of surface contact so there are more Van Der Waals forces which require more energy to overcome
4
Q
explain the effects of branching on boiling point
A
if a substance is branched there are fewer points of contact due to branching so reduced packing therefore the Van Der Waals forces are weaker so the substance has a lower boiling point
