A student following the procedure in this experiment prepared three solutions by adding 11.50, 23.00, and 34.50 mL of a 7.60 x 10-2M NaOH solution to 50.00 mL of a .112M solution of a weak acide. The solutions were labeled 1, 2, and 3 respectively. Each of the solutions was diluted to a total volume of 100 mL with distilled water. The pH readings of these solutions were (1) 6.42, (2) 6.81, and (3) 7.09.

1. Convert the pH of each solution to an equivalent H3O+ ion concentration.
2. For each solution, calculate the number of moles of acid added.
3. For each solution, calculate the number of moles of OH- ion added.
4. For each solution, determine the number of moles of HAn and An- ion at equilibrium.
5. For each solution, calculate the HAn and an- ion molar equilibrium concentrations.
6. Determine the reciprocal of the An- ion concentration for each solution.