What is the pH of a solution prepared by mixing equal volumes (50 mL each) of 0.10 M sodium acetate and 0.01 M acetic acid?
[Given pK_a of CH₃COOH = 4.57]
1. 2.57
2. 5.57
3. 3.57
4. 4.57

The following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations:

A)  $60$ $mL$ $\frac{M}{10}HCl$ $$ $+$ $40$ $mL$ $\frac{M}{10}NaOH$

B)   $55$ $mL$ $\frac{M}{10}HCl$ $$ $+$ $45$ $mL$ $\frac{M}{10}NaOH$

C)  $75$ $mL$ $\frac{M}{5}HCl$ $$ $+$ $25$ $mL$ $\frac{M}{5}NaOH$

D)  $100$ $mL$ $\frac{M}{10}HCl$ $$ $+$ $100$ $mL$ $\frac{M}{10}NaOH$

Which of them will have a pH equal to 1?

1. B
2. A
3. D
4. C