Final Answer:
The solution with [OH-] = 3.0 x 10^-10 is classified as b. basic.
Step-by-step explanation:
A solution's pH or pOH determines its acidity or basicity. When the hydroxide ion concentration exceeds the hydrogen ion concentration ([OH-] > [H+]), it indicates a basic solution. In this case, [OH-] = 3.0 x 10^-10 implies a low concentration of hydroxide ions, which suggests a higher concentration of hydrogen ions ([H+] < 1 x 10^-14, assuming a 25°C solution). As the solution is dominated by hydrogen ions and has a pH below 7, it falls into the acidic range.
Therefore, the solution is basic, as it has a low concentration of hydroxide ions and a corresponding high concentration of hydrogen ions, signifying an acidic nature due to the imbalance in favor of hydrogen ions.
Correct answer: b. basic