The diagram shows how a city manages its plastic waste.

The city generates a total of 80,000 kg of plastic waste in a year.
Calculate the mass of plastic waste that is not able to be recycled in the city.
The molecular formula of a monomer used to make a certain polymer is C8H12O4\text{C}_8\text{H}_{12}\text{O}_4C8H12O4. State the empirical formula of this monomer.