816 2 Wh en 12 mL of 02 M NaOH is added to 25 ml of 015 M HC

8.16 2. Wh en 12 mL of 0.2 M NaOH is added to 25 ml of 0.15 M HCI, what is the pH of the solution? When 12 mL of 0.2 M NaOH is added to 25 mL of 0.15 M acetic acid, would this solution be considered a buffer? Explain your answer 3. 4. What is the pH of the solution in number 3? How many mL of 0.1 M NaOH would you have to add to 30 mL of 0.35 M HCl to reach the equivalence point? 5.

Solution

2. Mmoles of NaOH = 0.2M*12mL = 2.4mmoles

Mmoles of HCl = 0.15M*25mL = 3.75mmoles

NaOH + HCl----> NaCl + H2O

Initial:2.4. 3.75 . 0 . 0

Change -2.4. -2.4. -2.4. -2.4

Equilb. 0 . 1.35. 2.4 . 2.4

Mmoles of HCl = 1.35mmoles.

Volume of HCl = 12mL + 35mL = 47mL

Molarity of HCl = 1.35mmoles/47mL = 0.0287M

pH = -log0.0287 = 1.54