CHEMISTRY · Subjective · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Phosphoric acid, H3PO4, is titrated with 0.100 M NaOH. A 35.0 mL sample of 0.100 M H3PO4 is brought to the first equivalence point by adding 35.0 mL of the base. Given Ka1=7.1×10−3, Ka2=6.3×10−8, and Ka3=4.2×10−13, calculate the pH of the solution at this first equivalence point. Report your answer to two decimal places.