Final answer:
To determine the pH after titration of CH₃COOH with NaOH, we calculate the remaining moles of CH₃COOH and perform an equilibrium calculation for the remaining weak acid. However, without the dissociation constant for CH₃COOH, the exact pH calculation cannot be completed.
Step-by-step explanation:
To calculate the pH after 25.00 mL of 0.20 M CH₃COOH is titrated with 40.00 mL of 0.10 M NaOH, we first need to find the amount of NaOH and CH₃COOH in moles. For NaOH, it is 0.0040 L × 0.10 M = 0.0004 mol. For CH₃COOH, it is 0.0250 L × 0.20 M = 0.0050 mol. After the reaction between NaOH and CH₃COOH, there will be excess CH₃COOH because it is present in a greater mole quantity (0.0050 mol CH₃COOH - 0.0004 mol NaOH = 0.0046 mol CH₃COOH remains).
The remaining CH₃COOH will affect the pH of the solution. Since CH₃COOH is a weak acid, we must use an equilibrium calculation to determine the pH. However, since the exact value for the dissociation of CH₃COOH is not provided, we cannot complete the calculation without it. Typically, the calculation would involve setting up an ICE table, calculating the concentration of H+ ions at equilibrium, and then using the pH = -log[H+] formula to find the pH.