Below are the reduction half reactions for chemolithoautotrophic denitrification, where hydrogen is a source of electrons and energy and nitrate is the terminal electron acceptor.
NO3- + 10e- -> N2 (E0 = +0.74 V)
H+ + 2e- -> H2 (E0 = -0.42 V)
If you balance and combine the reactions so that 90 moles of H2 gas are oxidized to H+, how many moles of N2 gas will be produced?