Polarity is a measure of the uneven distribution of electron density within a molecule. Polar molecules have a positive and a negative end due to differences in electronegativity between atoms.

Ethyl acetate (CH3COOCH2CH3) has a polar carbonyl group (C=O) and an oxygen atom attached to a carbon atom. The electronegativity difference between oxygen and carbon creates a partial positive charge on the carbon atom and a partial negative charge on the oxygen atom.

Petroleum ether is a mixture of alkanes, which are nonpolar hydrocarbons. Alkanes have only carbon-hydrogen bonds, and the electronegativity difference between carbon and hydrogen is very small. Therefore, petroleum ether has very low polarity.

In summary:

* Ethyl acetate has a polar carbonyl group and oxygen atom, making it more polar.

* Petroleum ether is a mixture of nonpolar alkanes, making it less polar.

Therefore, ethyl acetate is more polar than petroleum ether.