0.095 g of an unknown diprotic acid is titrated with 0.095 M NaOH. The first equivalence point occurred in the titration at a volume of 6.70 mL of NaOH added; the second equivalence point occurred at a volume of 13.40 mL of NaOH added. How many moles of NaOH were used to reach the first equivalence point in this diprotic acid titration