Before the reaction I had NaOH= 34.086g, P2O5= 38.295g and then added catechol= 5. after the reaction I have NaOH= 46.091g, P2O5= 38.

Im doing a combustion lab and need help. Before the reaction I had NaOH= 34.086g, P2O5= 38.295g and then added catechol= 5.006g. after the reaction I have NaOH= 46.091g, P2O5= 38.295. From the change in the P2O5 trap mass before and after the reaction, determine the mass of H2O produced by the catechol sample. Be careful to use the change in mass of each in mass of each trap for just before, and just after, the catechol sample is combusted.