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

When equal volumes of 0.1 M NaOH and 0.01 M HCl are mixed, the pH of the resulting solution will be:

Which of the following salts will give the highest pH in water?
1. KCl
2. NaCl
3. Na₂CO₃
4. CuSO₄

Which of the following equimolar solutions, prepared separately, will have the highest pH?