Using the solubility rules predict the precipitates

Question

KNO3(aq) and BaCI2 (aq)

 

Na2SO4 and Pb(NO3)2

 

KOH(aq) and Fe(NO3)3 (aq)

 

NaCI (aq) + AgNO3 (aq)

 

Na2SO4 (aq) + Ba(NO3)2 (aq)

Answer 1

Hi Vianne, 

I would like to help you with Solubility Rules. The process to receive an answer is simple. First, we will review the  solubility rules. Second, we will ^write down a balanced chemistry equation. Third, we will apply the rules to predict precipitates. 

 

The following are the rules used in chemistry to predict the precipitate. 

1. Salts containing Group I elements are almost always soluble. Salts contain the ammonium ion (NH4+) are also soluble.  There are few exceptions to this rule. 
2. Salts containing the (NO₃^-) are generally soluble.
3. Salts containing the Cl^-, Br^-, and I^- are soluble. There are few exceptions to this rule. The exceptions are Halide Salts of Ag⁺, Pb²⁺, and (Hg₂)²⁺.
4. Most silver salts are insoluble. The only exceptions of this rule are AgNO₃ and Ag(C₂H₃O₂). 
5. Most of the sulfate salts are soluble. Exceptions to this rule are CaSO₄, BaSO₄, PbSO₄, AgSO₄, and SrSO₄. 
6. Most hydroxide salts are only slightly soluble. Hydroxide salts of group I salts are soluble. Hydroxide salts of Group II elements (Ca, Sr, and Ba) are slightly soluble. Hydroxide salts of transition metals an Al³⁺ are insoluble.
7. Most of the sulfides of transition metals are insoluble. Arsenic, Antimony, Bismuth, and Lead sulfides are also insoluble.
8.  Almost always Carbonates, Chromates, Phosphates, and Fluorides are insoluble.

I will us the reaction of aqueous solutions of Potassium Nitrate and Barium Chloride. The reaction is as follows 

KNO₃(aq) + BaCl₂(aq) = KCl₂(?) + BaNO₃(?) the question marks indicate what we are trying to find out. According to the first and third rules of Solubility, we see that salts containing Potassium and the Chloride ion are soluble. The Second rule says that salts also soluble; however, I would predict Potassium Chloride would form a precipitate and Barium Nitrate would be aqueous. 

 

Now, you can apply this process to the other compounds and make your own predictions of which ones will precipitate and which ones will remain aqueous. I hope I have clarified the problem for you.