A buffer is prepared by mixing 110. mL of 0.442 M HCl and 0.545 L of 0.400 M sodium acetate. How many grams of KOH must be added to 0.500 L of the buffer to change the pH by 0.10 units?

Question

The pH I have calculated to be 5.28. What do I to figure this out?

I have a problem with this problem. A buffer is defined as a mixture of a weak acid and a salt of the weak acid (or a weak base and a salt of the weak base). This problem has HCl and sodium acetate and that is a strong acid with a salt of a weak acid. It isn't a buffer. Check the problem, please.