Which of the following six-carbon molecules can be a straight-chain alkyne with two triple bonds and no double bonds?

C6H4
C6H6
C6H8
C6H10

I chose C6H6, is this correct?

I agree

No, C6H6 is not correct. To determine which of the given molecules can be a straight-chain alkyne with two triple bonds and no double bonds, we can analyze the molecular formula.

Straight-chain alkynes are hydrocarbons with triple bonds between carbon atoms. Since we are looking for a molecule with two triple bonds, we know that it should have 4 carbon atoms, as each triple bond includes two carbon atoms.

Out of the given options, C6H4, C6H6, C6H8, and C6H10, we can eliminate C6H4 and C6H10 because they each have 6 carbon atoms.

Next, we need to consider the number of hydrogen atoms. In an alkyne, each carbon atom should bond with only one hydrogen atom. Therefore, we require 3 hydrogen atoms per carbon atom.

C6H6 has 6 carbon atoms and 6 hydrogen atoms. Since each carbon atom in an alkyne should have 3 hydrogen atoms, C6H6 does not meet the criteria, as it has one triple bond and three double bonds.

The correct answer is C6H8. It has 4 carbon atoms and 8 hydrogen atoms, which satisfies the requirements for a straight-chain alkyne with two triple bonds.

Therefore, the correct choice is C6H8.