Solution ph at buret readings plot a graph of ph versus volume of naoh solution added. from your graph determine the equivalence point, which is the point at which the graph is rising most steeply, and the ph at the half equivalence point. calculate k, for benzoic acid from your measurement look up the value of ka for benzoic acid in a reference source (cite the source you use) and compare it with your experimental value. calculate the equivalent weight of benzoic acid that is the weight which contains exactly one mole of titratable acid hydrogen. compare your calculated answer with that expected from the formula of benzoic acid, c6h5cooh (the only titratable (acidie) hydrogen in benzoic acid is the underlined one). discussion questions and problems: a) why can you not prepare a solution of ph = 8 by diluting sufficiently a 0.01 m solution of hcl with water? b) you could determine k, for benzoic acid by measuring the ph of a 0.010 m solution of benzoic acid. why is the graphical method used in this experiment a better way of determining ka? c) list the measurements along with their uncertainties made in the determination of the molar mass of benzoic acid. calculate the uncertainty in the molar mass of benzoic acid determined by the titration.