Asample of 0.0865 g of an unknown solid weak monoprotic acid, ha, was dissolved in 50.0 ml of water and titrated with 0.127 mol/l koh solution. thc volumc of the basc required to rcach the equivalence point was 9.20 ml a) what is the concentration of the acid? b) calculate the molar mass of the acid? c) after 4.60 ml of the base has been added, the ph of the solution is measured to be 4.89. calculate ka of the weak acid. identify the acid by comparing the ka value calculated from (c) with the list of ka value in the ycllow information shect (a copy of the yellow information shect can be found in the lab manual) d)