When NaOH is dissolved in water, which ions are present in the solution?

When NaOH is dissolved in water, which ions are present in the solution?

• A. Na+ and OH-
• B. Na+ and H+
• C. OH- only
• D. NaOH molecules in solution

Answer: (A)

When a strong base like NaOH is dissolved in water, it dissociates completely into ions. The solution contains Na+ ions and OH- ions because NaOH breaks apart into these two species in aqueous solution. The sodium ion acts as a spectator and doesn’t affect the basicity, while the hydroxide ion increases the pH. There are no intact NaOH molecules left in solution under ideal conditions. The presence of free H+ is not produced by NaOH; any hydronium from water’s autoionization is negligible in a strongly basic solution.

When a strong base like NaOH is dissolved in water, it dissociates completely into ions. The solution contains Na+ ions and OH- ions because NaOH breaks apart into these two species in aqueous solution. The sodium ion acts as a spectator and doesn’t affect the basicity, while the hydroxide ion increases the pH. There are no intact NaOH molecules left in solution under ideal conditions. The presence of free H+ is not produced by NaOH; any hydronium from water’s autoionization is negligible in a strongly basic solution.