I dont understand. Im in 7th its photosynthesis stuff and i dont understand.

Which compound contain an iron with a 3+ charge

What is the oxidation state of each individual carbon atom in c2o42−?

If you used the method of initial rates to obtain the order for no2, predict what reaction rates you would measure in the beginning of the reaction for initial concentrations of 0.200 m, 0.100 m, & 0.050 m no2.