You are asked to determine the alkali present and the percentage of each in a component of a sample material containing components of NaOH, Na,CO, and NaHCO, or mixtures of this together with inert material. Each sample being tested weighs 2g and uses 0.25N hydrochloric acid for neutralization. Sample 1: Using phenolphthalein indicator, 48.64ml acid was used. A duplicate sample needed 97.28ml of acid was used with methyl orange indicator. Sample 2: No color change using phenolphthalein as an indicator but with methyl orange 76.94ml acid is required. Sample 3. To cause a color change, the sample was titrated cold with phenolphthalein, 30.58ml of acid is necessary, and an additional 33.19ml was required for complete neutralization

Let HA represent a weak acid. A 10.0 mL sample of 0.60 M HA was titrated with 0.30 M NaOH. The following data were collected during the titration. Volume NaOH added (mL) 10.00 12.50 20.00 25.00 pH 7.46 7.99 10.31 12.63 What is the Ka for HA? 1.2 x 10-8 1.0 x 10-7 4.9 × 10-11 None of these 3.5 x 10-8

How many milliliters (mL) of 5.0 M HCl should be added to 26.6 g of sodium borate to give a pH of 9.00 in a final volume of 100 mL. Given: nboric acid pKa = 9.15 and sodium borate MW = 381.37 g/mole. Report the value to 3 significant figures and with units.

a) Compare between equivalence point and endpoint. Distinguish which point comes first. b) James performed an acid base titration experiment. A 25 mL sample containing HCl was transferred to Erlenmeyer flask using volumetric pipette. HCl sample was titrated against standardized 0.5010 M NaOH. An average titre volume of 24.35 mL was reported. Suggest a suitable pH indicator for James to be used in this experiment. Predict the initial concentration of the HCl. c) Alan and friends wish to sketch a weak acid strong base titration curve. Before they can do so, they need some data points. In a case where 50 mL of 0.20 M CH3COOH (Ka = 1.80 x 10-5 ) was titrated with 0.05 M NaOH, deduce the pH after addition of different volumes of NaOH. (i) 0 mL NAOH (ii) 100 mL NaOH (iii) 200 mL NaOH