Alkanes and alkenes question (1 Viewer)

[erucibon]

(From 2002 HSC Q17)
Explain why alkanes and their corresponding alkenes have similar physical properties, but very different chemical properties.

Would specific points would you talk about with this question and what does specific physical (intermolecular forces for MP BP?) and chemical (something to do with UV light?) properties does it refer to?
Thanks

 

[jazz519]

Intermolecular forces - affect physical properties (why because intermolecular forces means interactions between different molecules in a substance)
Alkanes and alkenes are both non-polar. So therefore they only have dispersion forces which means they have low boiling point. Also, their non-polar nature means they are insoluble in water and soluble in non-polar things like hexane.

Intramolecular forces - affect chemical properties (why because intramolecular force means what type of bonding there is in an a molecule. The reason or way something reacts is all down to what functional groups it has and if those groups are double bonded and triple bonded also has an influence)
Alkanes have single bonds, while alkenes have double bonds. So therefore they react in different ways because the bonding is different. For example, alkenes can undergo addition reactions like: C2H4(g) + Cl2(g) --> C2H4Cl2(g), while alkanes can't do those types of reactions