Final answer:
To rank the hydrocarbons from weakest to strongest C-C bond, the order is ethane, ethene, and ethyne.
Step-by-step explanation:
To rank the hydrocarbons from weakest to strongest C-C bond, we need to consider the types of bonds present in each compound. Ethane (C₂H₆) has all single bonds, ethene (C₂H₄) has a double bond, and ethyne (C₂H₂) has a triple bond between its carbon atoms. Propane (C₃H₈) is not relevant to this comparison, as it has three carbon atoms instead of two. A triple bond is the strongest, followed by a double bond, and then a single bond. Therefore, the ranking from weakest to strongest C-C bond would be ethane, ethene, and ethyne.