Question

iewusg.edu/d2/le/content/1845236/viewContent/27964232/View To improve the quality of X-ray photos used in the diagnosis of intestinal disorders the patient drinks an aqueous suspension of BaSOg before having the X-ray. However, BaSO4 is slightly soluble (Ksp 1.1 x 10-10) and Ba2 is toxic. Which of the following compounds would be the best to add to the suspension in order to make it less concentrated in Ba2+ and less toxic to the patient? 2t BasOy Ba no effect A. NaNO3 B. Ba(NOs)2 t0 50lubk, CB no cffect C. NaCl DNa SO 1 CS o shitt egushb CBa harmfal for the patunt to drint Hsy 42 E. H2SO

please explain the answers for these (such as why a decrease in pH would have no affect in some of the molecules in picture #2)

Answer 1

Pic: 2

If anion in the salt is from the weak acid, it gets hydrolysed and concentration of anion deceased , which would increases the solubility of salt .

Hg₂Cl₂ and PbI₂ has no effect on the increases of [H⁺] (or decreases of pH) because Cl^- + H⁺ gives HCl . HCl is strong acid and dissociate completely and hence [Cl^-] does not change . Similarly HI is strong acid and dissociate completely. Hence there is no effect on their solubility by decreasing the pH .

Ag₃PO₄ and PbS are salts of weak acid H₃PO₄ and H₂S , their solubility increases on decreasing pH. Cd(OH)₂ is more soluble on decreasing pH because increased [H⁺] would consume OH^- and shift the equilibrium towards right .

Hence answer:(D)-(i), (IV) , (v)

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Pic:3

Le Chatelier principle says , if equilibrium is put under stress , equilibrium will shift in that direction which will oppose the applied stress.

Addition of Mg(NO₃)₂ would increases [Mg²⁺] but equilibrium would try to decrease it . That means equilibrium shifts backward and solubility of Mg(OH)₂ decreases .

Addition of KOH increases [OH^-] , hence again equilibrium shifts backward and solubility decreases .

Addition of HCl , would consume OH^-, system would try to produce OH^- and equilibrium shift towards right and solubility increases .