Sorry, I didn't finish the question:
Which of the following will increase the molar sollubility of Ag2CO3? (The Ksp for Ag2CO3 is 8.1 x 10^12.)
a. Add HCl
b. Add AgNO3
c. Add NaCN
d. a and c
e. a, b, and c
Ag2CO3 --> 2Ag^+ + CO3^-2
What will HCl do. It reacts with CO3^- (remember the reaction with acid to produce CO2 and H2O), so reaction shifts to the right and solubility is increased.
b. Add AgNO3. That is a common ion, Ag^+ is increased so reaction shifts to the left. Solubility decreased.
c. Add NaCN. CN^- reacts with Ag^+ to produce Ag(CN)2^-. That removes Ag^+ from soln, reaction shifts to right. Solubility increases.
To determine which of the options will increase the molar solubility of Ag2CO3, we need to understand how factors such as common ion effect and complex formation affect solubility.
Option a. Add HCl: When HCl (hydrochloric acid) is added, it dissociates into H+ and Cl- ions. The chloride ions (Cl-) are a common ion with Ag2CO3, as Ag2CO3 also contains Cl- ions. According to the common ion effect, the presence of a common ion decreases the solubility of a compound. Therefore, adding HCl will actually decrease the molar solubility of Ag2CO3. So option a will not increase the molar solubility.
Option b. Add AgNO3: When AgNO3 (silver nitrate) is added, it dissociates into Ag+ and NO3- ions. Since Ag2CO3 already contains Ag+ ions, adding more Ag+ ions through AgNO3 will increase the concentration of Ag+ ions in the solution. According to Le Chatelier's principle, an increase in the concentration of one of the ions involved in a precipitation reaction leads to a shift in equilibrium towards solubilization. Therefore, adding AgNO3 will increase the molar solubility of Ag2CO3.
Option c. Add NaCN: When NaCN (sodium cyanide) is added, it dissociates into Na+ and CN- ions. Cyanide ions (CN-) have a high affinity for Ag+ ions, forming a complex ion called Ag(CN)2-. This complex ion is more soluble than Ag2CO3 itself. Therefore, adding NaCN will increase the molar solubility of Ag2CO3.
Option d. a and c: We have already established that adding HCl will decrease the molar solubility of Ag2CO3, so option d is incorrect.
Option e. a, b, and c: Since options a and b have opposite effects on the solubility of Ag2CO3, adding both HCl and AgNO3 simultaneously will not have a definite answer. However, adding NaCN along with HCl and AgNO3 will increase the molar solubility of Ag2CO3, as explained before. Therefore, option e is the correct answer.
In summary, the options that will increase the molar solubility of Ag2CO3 are b (Add AgNO3), c (Add NaCN), and e (Add HCl, AgNO3, and NaCN).