Someone is attempting to measure the H3PO4(aq) content of an unknown solution by both titration with NaOH(aq) and calorimetry. The person measures 100 mL of stock NaOH(aq) solution into a buret but forgets to write down its concentration. They then measure out 50.0 mL of unknown H3PO4(aq) solution (which has an indicator) and places this solution in a constant-pressure calorimeter for the titration experiment. The initial temperature of all the solutions is 22.9 Celsius. The student adds 46.84 mL of NaOH(aq) from the buret to the H3PO4(aq) solution in the calorimeter to reach the equivalence point (color change for indicator). The final solution temperature is 33.5 Celsius. Assume density and specific heat of all solutions are the same as that of pure water and that volumes are additive.    a) what is the balanced molecular equation for the acid-base reaction that takes place in the calorimeter? b) Calculate delta HRXN (enthralpy) for the above acid-base reaction c) what is the concentration (in M) of the unknown H3PO4 solution?

Someone is attempting to measure the H₃PO₄(aq) content of an unknown solution by both titration with NaOH(aq)

and calorimetry. The person measures 100 mL of stock NaOH(aq) solution into a buret but forgets to write down its concentration. They then measure out 50.0 mL of unknown H₃PO₄(aq) solution (which has an indicator) and places this solution in a constant-pressure calorimeter for the titration experiment. The initial temperature of all the solutions is 22.9 Celsius. The student adds 46.84 mL of NaOH(aq) from the buret to the H₃PO₄(aq) solution in the calorimeter to reach the equivalence point (color change for indicator). The final solution temperature is 33.5 Celsius. Assume density and specific heat of all solutions are the same as that of pure water and that volumes are additive. 

a) what is the balanced molecular equation for the acid-base reaction that takes place in the calorimeter?

b) Calculate delta H_RXN (enthralpy) for the above acid-base reaction

c) what is the concentration (in M) of the unknown H₃PO₄ solution?