Answer to Question #114957 in Chemistry for tristan

Question

Which of the following bases produces two OH- ions per formula unit of base when dissolved in water?
Ammonia
Aluminum hydroxide
Potassium hydroxide
Calcium hydroxide

Answer 1

Solution:

1) Ammonia 

When NH₃ is dissolved in H₂O (water) it will dissociate (dissolve) into one NH₄⁺ ion and one OH^- ion.

NH₃(aq) + H₂O(l) = NH₄⁺(aq) + OH^-(aq)

2) Aluminum hydroxide

When Al(OH)₃ is dissolved in H₂O (water) it will dissociate (dissolve) into one Al³⁺ ion and three OH^- ions. 

Al(OH)₃(s) = Al³⁺(aq) + 3OH^-(aq)

3) Potassium hydroxide 

When KOH is dissolved in H₂O (water) it will dissociate (dissolve) into one K⁺ ion and one OH^- ion.

KOH(aq) = K⁺(aq) + OH^-(aq)

4) Calcium hydroxide

When Ca(OH)₂ is dissolved in H₂O (water) it will dissociate (dissolve) into one Ca²⁺ ion and two OH^- ions.

Ca(OH)₂(s) = Ca²⁺(aq) + 2OH^-(aq)

Answer: Calcium hydroxide produces two OH^- ions when dissolved in water.