Fill in the blanks in the following sentences:
a. A solution having a pH equal to 7 at 25 o C is ………………… .. solution.
b. A solution having a pH greater than 7 at 25 o C is …… ..... Solution.
c. A solution having a pH less than 7 at 25 o C is ……………… .solution.
d. Between two solutions of sodium hydroxide having pH values 13 and 12, the most basic is the solution that has pH ……