[SPM Chemistry Question] How to solve this question?

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Chemistry Question

  1. Rajah 11 menunjukkan formula struktur bagi suatu hidrokarbon.
    Diagram 11 shows the structural formula of a hydrocarbon.
    Apakah nama bagi hidrokarbon itu mengikut penamaan IUPAC?
    What is the name of the hydrocarbon based on IUPAC nomenclature?

A 2,3,4-trimetilpentana
B 2 -etil-2,4-dimetilpentana
C 2,4 -dimetil-4-etilpentana
D 2,4,4-trimetilheksana

Chemistry Solution

I will explain how to solve in the following steps:

  1. Start by identifying the longest chain. With 6 carbons, this implies the carbon compound belongs to the “hexane” category.
  2. Number the carbon chain in a way such that the first methyl group is attached to the lowest possible number of the carbon atom within the chain. In this case, the 2nd carbon atom is connected to one methyl group, and the 4th carbon atom is connected to two methyl groups.

The full IUPAC name will therefore be: 2,4,4-trimethylhexane. Answer is D.

Proof for answer:2,4,4-trimethylhexane


Extra notes (Wrong answer):


If you number the carbon chain such that the two methyl groups connected to the carbon is of a lower number, it would be the third carbon and the fifth carbon is connected to another methyl group, leading to a final IUPAC name of 3,3,5-trimethylhexane, which is wrong as the carbon atom with the lowest number for naming should be prioritised.

Similar question is found here for your reference: [SPM Chemistry Hydrocarbon Q40 Solution] Carbon Carbon compound

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Oohhh Thank you very much !:blush::+1::+1:

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