5. Reactions in Solution Precipitation Page 14 Partner: Jeff Somvorachith 10/31/24 Lab 5. Reactions in Solution Precipitation Purpose: To practice identifying reactions that result in precipitation and practice recognizing and writing equations for double replacement reactions by testing pairs of reagents and looking for signs of chemical change and writing molecular and ionic equations for the reactions. Prelab:  a. Zinc Sulfide: ZnS b. Chromium(III) Hydroxide: Cr(OH) 3 c. Lead(II) Phosphate: Pb 3 (PO 4 ) 2 a. Sodium Chloride: NaCl->Na + +Cl - b. Copper(II) Chloride: CuCl 2 ->Cu 2+ +2Cl - c. Iron(III) Sulfate: Fe 2 (SO 4 ) 3 ->2Fe 3+ +3SO 4 2-  Fe(NO 3 ) 3 +K 2 CO 3 ->Fe 2 (CO 3 ) 3 (s)+KNO 3 0.2M*1L=M 1 *2L M 1 = 0.1M Procedure: Use 4-5 drops of each reagent for each pair of your tests. Note and record any sign of reaction. Test all possible pair of combinations of one group A reagent with one group B reagent. Record your observations in the data table in your notebook. Recall that not all pairs will react, and that sometimes the evidence of reaction, especially formation of a precipitate, take a few moments to appear. If there are any combinations about which you doubt, repeat the tests. Return pipettes containing unused portions of the reagent Page 15 solutions to the proper location. Some of the solutions contain transition metal ions, so should not be washed down the drain. Instead, dump the contents onto a paper towel in the tray labeled "transition metal waste". Wash some items with water and clean others with cotton swabs.  Safety: Barium is toxic, don't touch. wash hands thoroughly. Data Table: CoCl 2 CuCl 2 AlCl 3 BaCl 2 NiCl 2 NaI No Reaction Turned Brown, Precipitated No Reaction No Reaction No Reaction Na 2 CO 3 Precipitated Precipitated Precipitated Precipitated Precipitated Na 3 PO 4 Tuned Purple, Precipitated Precipitated Precipitated Precipitated Precipitated Na 2 SO 4 No Reaction No Reaction No Reaction Precipitated No Reaction NaOH Turned Purple, Precipitated Precipitated Precipitated Precipitated Precipitated Page 16 Conclusion: a. Formula of Precipitates CoCl 2 CuCl 2 AlCl 3 BaCl 2 NiCl 2 NaI CuI 2 Na 2 CO 3 CoCO 3 CuCO 3 Al 2 (CO 3 ) 3 BaCO 3 NiCO 3 Na 3 PO 4 Co 3 (PO 4 ) 2 Cu 3 (PO 4 ) 2 AlPO 4 Ba 3 (PO 4 ) 2 Ni 3 (PO 4 ) 2 Na 2 SO 4 BaSO 4 NaOH Co(OH) 2 Cu(OH) 2 Al(OH) 3 Ba(OH) 2 Ni(OH) 2 b. Molecular Formulas CuCl 2 ​ ( a q ) + 2 NaI ( a q ) -> 2 CuI 2 ( s ) + 2 NaCl ( a q ) CoCl 2 ​ ( a q ) + Na 2 ​ CO 3 ​ ( a q ) -> CoCO 3 ​ ( s ) + 2 NaCl ( a q ) CuCl 2 ​ ( a q ) + Na 2 ​ CO 3 ​ ( a q ) -> CuCO 3 ​ ( s ) + 2 NaCl ( a q ) 2 AlCl 3 ​ ( a q ) + 3 Na 2 ​ CO 3 ​ ( a q ) -> Al 2 ​ ( CO 3 ​ ) 3 ​ ( s ) + 6 NaCl ( a q ) BaCl 2 ​ ( a q ) + Na 2 ​ CO 3 ​ ( a q ) -> BaCO 3 ​ ( s ) + 2 NaCl ( a q ) NiCl 2 ​ ( a q ) + Na 2 ​ CO 3 ​ ( a q ) -> NiCO 3 ​ ( s ) + 2 NaCl ( a q ) 3 CoCl 2 ​ ( a q ) + 2 Na 3 ​ PO 4 ​ ( a q ) -> Co 3 ​ ( PO 4 ​ ) 2 ​ ( s ) + 6 NaCl ( a q ) 3 CuCl 2 ​ ( a q ) + 2 Na 3 ​ PO 4 ​ ( a q ) -> Cu 3 ​ ( PO 4 ​ ) 2 ​ ( s ) + 6 NaCl ( a q ) AlCl 3 ​ ( a q ) + Na 3 ​ PO 4 ​ ( a q ) -> AlPO 4 ​ ( s ) + 3 NaCl ( a q ) 3 BaCl 2 ​ ( a q ) + 2 Na 3 ​ PO 4 ​ ( a q ) -> Ba 3 ​ ( PO 4 ​ ) 2 ​ ( s ) + 6 NaCl ( a q ) 3 NiCl 2 ​ ( a q ) + 2 Na 3 ​ PO 4 ​ ( a q ) -> Ni 3 ​ ( PO 4 ​ ) 2 ​ ( s ) + 6 NaCl ( a q ) BaCl 2 ​ ( a q ) + Na 2 ​ SO 4 ​ ( a q ) -> BaSO 4 ​ ( s ) + 2 NaCl ( a q ) CoCl 2 ​ ( a q ) + 2 NaOH ( a q ) -> Co(OH) 2 ​ ( s ) + 2 NaCl ( a q ) CuCl 2 ​ ( a q ) + 2 NaOH ( a q ) -> Cu(OH) 2 ​ ( s ) + 2 NaCl ( a q ) AlCl 3 ​ ( a q ) + 3 NaOH ( a q ) -> Al(OH) 3 ​ ( s ) + 3 NaCl ( a q ) BaCl 2 ​ ( a q ) + 2 NaOH ( a q ) -> Ba(OH) 2 ​ ( s ) + 2 NaCl ( a q ) NiCl 2 (aq)+2NaOH(aq)->Ni(OH) 2 (s)+2NaCl(aq) Page 17 11/1/24 c. Net ionic formulas Cu 2+ +2I + ->CuI 2   Co 2+ +Co 3 2- ->CoCO 3 Cu 2+ +Co 3 2+ ->CoCO 3 2Al 3+ +3CO 3 2- ->Al 2 (CO 3 ) 3 Ba 2+ +CO 3 2- ->BaCO 3 Ni 2+ +CO 3 2- ->NiCO 3 3Co 2+ +2PO 4 3- ->Co 3 (PO 4 ) 2 3Cu 2+ +2PO 4 3- ->Cu 3 (PO 4 ) 2 Al 3+ +PO 4 3- ->AlPO 4 3Ba 2+ +2PO 4 3- ->Ba 3 (PO 4 ) 2 3Ni 2+ +2PO 4 3- ->Ni 3 (PO 4 ) 2 Ba 2+ +SO 4 2- ->BaSO 4 Co 2+ +2OH - ->Co(OH) 2 Cu 2+ +2OH - ->Cu(OH) 2 Al 3+ +3OH - ->Al(OH) 3 Ba 2+ +2OH - ->Ba(OH) 2 Ni 2+ +2OH - ->Ni(OH) 2