Using general solubility rules, write the balanced molecular equation when the following aq solutions are mixed. Underline the formula of the solid. If no precipitation reaction is likely, explain why.
A. NHY4Cl, H2SO4
B. K2CO3, SnCl4
C. NH4Cl, Pb(NO3)2
D. CuSO4, KOH
E.Na3PO4, CrCl3
F. (NH4)2S, FeCl3
You need to know the solubility rules. Here is a simple set of rules that will cover most (not all) salts.
http://www.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
For example, NH4Cl + H2SO4.
the possible combinations, if you look at a double replacement reaction, is HCl + NH4SO4. By the rules, ammonium salts are soluble so there is no ppt.
To determine if a precipitation reaction will occur when two aqueous solutions are mixed, you can use general solubility rules. These rules are guidelines that help identify the products of a chemical reaction based on the solubility of different compounds in water.
Here are the general solubility rules to consider:
1. All nitrate (NO3-) and acetate (CH3COO-) salts are soluble.
2. Most salts of alkali metals (Li+, Na+, K+, etc.) and ammonium (NH4+) are soluble.
3. Most chloride (Cl-), bromide (Br-), and iodide (I-) salts are soluble, except those of silver (Ag+), lead (Pb2+), and mercury (Hg22+).
4. Most sulfate (SO42-) salts are soluble, except those of calcium (Ca2+), strontium (Sr2+), barium (Ba2+), lead (Pb2+), and silver (Ag+).
5. Most hydroxide (OH-) salts are only slightly soluble, except those of alkali metals (Li+, Na+, K+, etc.), ammonium (NH4+), and barium (Ba2+).
6. Most sulfide (S2-) salts are only slightly soluble, except those of alkali metals (Li+, Na+, K+, etc.) and ammonium (NH4+).
7. Most carbonate (CO32-) and phosphate (PO43-) salts are only slightly soluble, except those of alkali metals (Li+, Na+, K+, etc.) and ammonium (NH4+).
Now, let's go through each pair of solutions and determine if a precipitation reaction will occur and write the balanced molecular equation if it does.
A. NH4Cl, H2SO4
Both NH4+ and Cl- ions are soluble based on the solubility rules. Therefore, no precipitation reaction is expected.
Balanced molecular equation: No reaction occurs.
B. K2CO3, SnCl4
According to the solubility rules, K2CO3 is soluble, while SnCl4 is not. Therefore, a precipitation reaction is expected.
Balanced molecular equation: K2CO3(aq) + SnCl4(aq) -> KCl(aq) + SnCO3(s)
C. NH4Cl, Pb(NO3)2
Both NH4+ and NO3- ions are soluble based on the solubility rules. Therefore, no precipitation reaction is expected.
Balanced molecular equation: No reaction occurs.
D. CuSO4, KOH
Both Cu2+ and SO42- ions are soluble, while KOH is slightly soluble based on the solubility rules. Therefore, a precipitation reaction is not expected.
Balanced molecular equation: No reaction occurs.
E. Na3PO4, CrCl3
Both Na3PO4 and CrCl3 contain ions that have limited solubility based on the solubility rules. Therefore, a precipitation reaction is expected.
Balanced molecular equation: 2Na3PO4(aq) + 3CrCl3(aq) -> 6NaCl(aq) + Cr2(PO4)3(s)
F. (NH4)2S, FeCl3
Both (NH4)2S and FeCl3 contain ions that have limited solubility based on the solubility rules. Therefore, a precipitation reaction is expected.
Balanced molecular equation: 3(NH4)2S(aq) + 2FeCl3(aq) -> 6NH4Cl(aq) + Fe2S3(s)
By applying the general solubility rules, you can determine if a precipitation reaction will occur when two aqueous solutions are mixed and write the balanced molecular equation for the reaction.