Gasoline and naphtha are both mixtures of hydrocarbons, not single molecules. Therefore, it's not accurate to say one is a "larger molecule" than the other.

However, generally, naphtha has a higher average molecular weight than gasoline. This means that the hydrocarbons in naphtha tend to be larger than the hydrocarbons in gasoline.

Here's why:

* Naphtha is typically defined as a petroleum fraction with a boiling point range of 30-200 °C. This means it includes hydrocarbons with a wider range of chain lengths, including some larger ones.

* Gasoline has a narrower boiling point range (typically 30-200 °C), and thus, the hydrocarbons it contains have smaller average chain lengths.

To summarize: While both are mixtures, naphtha tends to have a higher average molecular weight and contains larger hydrocarbons than gasoline.