Help can someone check my work

Question

Draw the condensed formulas of 3-hexene and 2-methylbutane

3-hexene

CH3CH2CH=CHCH2CH3

2-methylbutane



CH3

|

CH3-CH-CH2-CH3

Draw the structural formula of 3-pentyne. What is wrong with this name?

CH2=CH-CH-CH3

|

CH3

the name should be 3-Pentane

Answer 1

Your first answer is correct, but the others are incorrect. I'll try to draw them, and hope they come out looking like they should.

2-methylbutane

CH3-CH2-CH-CH3

|

CH3

3-pentyne

CH3-C≡C-CH2-CH3 (that's a triple bond between C3 and C4 counting from the left)

The name should be 2-pentyne. You cannot have 3-pentyne