How can I tell if the following equations produce precipitates or not?
1. HgCl2 (aq) + K2CrO4 (aq) ==>
2. Ba(OH)2 (aq) + NaClO3 (aq) ==>
3. ZnI2 (aq) + CaSO4 (aq) ==>
4. SnCl2 (aq) + MgBr2 (aq) ==>
Here is a chart of solubility rules.
http://www.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html
To determine if the given equations produce precipitates or not, you need to first identify the possible products of the reactions and then check if any of those products are insoluble or form precipitates.
1. HgCl2 (aq) + K2CrO4 (aq) ==>
To determine if a precipitate forms, you need to know the solubility rules for common ionic compounds. In this case, the possible products are HgCrO4 and KCl. Referring to solubility rules, HgCrO4 is insoluble and forms a yellow precipitate, while KCl is soluble. Therefore, a precipitate of HgCrO4 will form.
2. Ba(OH)2 (aq) + NaClO3 (aq) ==>
The possible products of this reaction are Ba(ClO3)2 and NaOH. Referring to solubility rules, Ba(ClO3)2 is soluble, and NaOH is also soluble. Therefore, no precipitate will form in this case.
3. ZnI2 (aq) + CaSO4 (aq) ==>
The possible products in this equation are ZnSO4 and CaI2. By referring to solubility rules, ZnSO4 is soluble, and CaI2 is also soluble. Hence, no precipitate forms here.
4. SnCl2 (aq) + MgBr2 (aq) ==>
The possible products of this reaction are SnBr2 and MgCl2. Checking the solubility rules, SnBr2 is soluble, and MgCl2 is also soluble. Therefore, no precipitate will form in this reaction.
Remember, understanding the solubility rules and knowing the possible products of a reaction are crucial in determining the formation of precipitates.