Question

How is the concentration of OH\(^-\) ion affected on adding a base in excess to sodium hydroxide solution?

Hint:

Adding more base to a solution increases the concentration of OH\(^-\) ions, making the solution more alkaline.

Answer 1

When a base (such as NaOH) is added in excess to a sodium hydroxide solution, the concentration of OH\(^-\) ions increases. This happens because bases release hydroxide (\( OH^- \)) ions in aqueous solution, increasing alkalinity. \[ \text{NaOH} \rightarrow \text{Na}^+ + \text{OH}^- \] Effects of increasing OH\(^-\) concentration:
- The pH of the solution increases.
- The solution becomes more basic.
- The reactivity of the solution with acids increases.