Question

which of these is not a strong base? naoh ca(oh)₂ koh al(oh)₃

Explanation:

Strong bases are typically hydroxides of Group 1 (alkali metals) and some Group 2 (alkaline earth metals) metals that dissociate completely in water. NaOH (sodium hydroxide) and KOH (potassium hydroxide) are Group 1 hydroxides, strong bases. \( \text{Ca(OH)}_2 \) (calcium hydroxide) is a Group 2 hydroxide and a strong base (though slightly less soluble, it dissociates completely in solution). \( \text{Al(OH)}_3 \) (aluminum hydroxide) is an amphoteric substance and a weak base, as it does not dissociate completely to release \( \text{OH}^- \) ions.

Answer:

D. \( \text{Al(OH)}_3 \)