Question

For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with pH. If the solubility does change, pick the pH at which you'd expect the highest solubility. You'll find Ky data in the ALEKS Data tab. compound Does solubility change with PH? | highest solubility pH = 1 | pH = 6 | pH = 4 O yes Ba(OH), no Ca(OH)2 yes О по Caci, no x o ?

Answer 1

Ans :-

compound	Does solubility change with pH?	highest solubility
		pH = 7	pH = 6	pH = 4
Ba(OH)2	Yes			correct
Ca(OH)2	Yes			correct
CaCl2	No

Explanation :-

(a). Solubility equation of Ba(OH)₂ is :

Ba(OH)₂ (s) <-----------------> Ba²⁺ (aq) + 2 OH^- (aq)

As, we add more basic solution (pH larger), this will increase the concentration of OH^- in the products side and according to Le-Chatelier's principle equilibrium will shifts in backward direction where solubility decreases. So, Maximum solubility of Ba(OH)₂ would be in lowest pH i.e. at pH = 4.

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(b). Solubility equation of Ca(OH)₂ is :

Ca(OH)₂ (s) <-----------------> Ca²⁺ (aq) + 2 OH^- (aq)

As, we add more basic solution (pH larger) concentration of OH^- increases in the products side and according to Le-Chatelier's principle equilibrium will shifts in backward direction where solubility decreases. So, Maximum solubility of Ca(OH)₂ would be in lowest pH i.e. at pH = 4.

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(c). Solubility equation of CaCl₂ is :

CaCl₂ (s) <-----------------> Ca²⁺ (aq) + 2 Cl^- (aq)

As,CaCl₂ is the salt of strong base Ca(OH₂) and strong acid HCl. So its solubility will not changes with change in pH.