ek vs tpr in Alkane Physical properties

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TPR says that for an alkane, the melting and boiling points increase as the weight increases. it also says the melting and the boiling points decreases as branching incerases. this is page 73 in the organic chem review book

EK on the other hand says branching increases melting point but decreases the boiling point because branched alkanes are more compact which weakens the vander walls forces and lowers bp but the smae compact structure allows the alkane to be packed into a liquid raising the melting point.

??

 

[member232]

The trend for boiling point is pretty clean, as branching increases, boiling point decreases because of weakened intermolecular forces.

Melting point trends are not as clean of a trend, which is probably why both books have different trends.

I've had multiple practice questions about boiling point trends, but none so far on melting point trends regarding alkanes... I would just know the bp one, and IF you get a question on mp, use the passage or the context to see what they're trying to test you on

 

[Raiden2012]

The trend for boiling point is pretty clean, as branching increases, boiling point decreases because of weakened intermolecular forces.

Melting point trends are not as clean of a trend, which is probably why both books have different trends.

I've had multiple practice questions about boiling point trends, but none so far on melting point trends regarding alkanes... I would just know the bp one, and IF you get a question on mp, use the passage or the context to see what they're trying to test you on

Agreed. I had the same problem because I was referring to both material. So this question has been addressed on sdn a couple times before and the consensus was that melting point increases with increased branching. However, I've never encountered any questions regarding MP either. Like the above poster said, refer to text if necessary.