69. Solving a chemistry problem

12. A 5 ml mixture containing nitric and acetic acids was transferred to a 200 ml volumetric flask and made up to the mark with distilled water. 10 ml of the resulting solution was titrated with 0.125 M sodium hydroxide solution. 2.1 ml went to the first titration jump, and 1.5 ml of titrant went to the second. Determine the mass fractions of acids in the initial mixture, if we assume the density of the mixture is 1.0 g/cm3. Propose a system of electrodes for this titration.