Post Lab Number Eight Reactions in Aqueous Solution - Double Displacement Reactions PDF

Preview

Summary

Download Post Lab Number Eight Reactions in Aqueous Solution - Double Displacement Reactions PDF

Description

Nhi Chung General Chemistry I - Chem 1411, HCC 20 November, 2017

Post Lab n. 8 Reactions in Aqueous Solution – Double Displacement Reactions INTRODUCTION The purpose of this experiment is to identify the ions, combine solutions that may or not have reactions, and understand with writing equations such as metathesis reactions and net ionic equations. The aqueous solution is very important when it comes to determining whether or not a substance is dissolved or solvent. Furthermore, the metathesis reactions will be: AX + BY —> BX + AY for most substances that are soluble. Therefore, the solubility rules can be used to figure out the products' balanced formula equation, complete ionic equation, and net ionic equation, which are useful for identifying their reactants. EXPERIMENTAL This experiment was done by either working independently, with a partner, or group of four people when using the reactions, observing, and taking notes on the lab report sheet. The spot, clear plates was used for using the reactions and mixing them with a glass stirring rod. Moreover, it was important not to have some solutions on the hands because they could have ended up some serious contamination. Therefore, it was recommended to wear gloves or use a paper towel to protect the hands when giving a few drops (about four to five drops of each bottles of reactants) of reactions. More importantly, the observations should be discussed with a lab partner or group of four people to analyze and write the given chemical equations on the lab report sheet.

Some solutions turned thick and cloudy, which had to do with their formation of fine that separated solid particles of a solid precipitate. However, some solutions did not have any changes in their solid precipitate, which meant that no reactions occurred. Therefore, if there were reactions with any solutions, then observations must be recorded on the lab report sheet. If there were no reactions with any solutions, then they must be recorded as well. Most importantly, each of the reactions was written by the balanced molecular equation, complete ionic equation, and net ionic equation. DATA 1. By mixing barium chloride, BaCl2 (aq), with sodium sulfate, Na2SO4 (aq), a white precipitate is observed due to the formation of BaSO4 (s) which is insoluble according to the solubility rule. The reaction can be written as BaCl2 (aq) + Na2SO4 (aq) —> BaSO4(s) + 2NaCl (aq) The ionic for the equation is Ba2+ (aq) + 2Cl- (aq) + SO4- (aq) + 2Na+ (aq) —> BaSO4(s) + 2Na+ (aq) + 2Cl- (aq) The net ionic equation is Ba2+ (aq) + SO4- (aq) —> BaSO4 (s) + 2Na+ (aq) + 2Cl- (aq) 2. By mixing silver nitrate, Ag(NO3)2 (aq), with sodium chloride, NaCl (aq), a bright, cloudy white precipitate is observed due to the formation of AgCl2 (s) which is insoluble according to the solubility rule. The reaction can be written as Ag(NO3)2 (aq) + NaCl (aq) —> AgCl2 (s) + 2NaNO3 (aq) The ionic for the equation is

Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq) —> AgCl (s) + Na+ (aq) + NO3- (aq) The net ionic equation is Ag+ (aq) + Cl- (aq) —> AgCl (s) 3. By mixing lead (II) nitrate, Pb(NO3)2 (aq), with potassium iodide, KI (aq), a thick, bright yellow precipitate is observed due to the formation of PbI2 (s) which is insoluble according to the solubility rule. The reaction can be written as Pb(NO3)2 (aq) + KI (aq) —> PbI2 (s) 2KNO3 (aq) The ionic for the equation is Pb2+ (aq) + 2NO3- (aq) + 2K+ (aq) + 2I- (aq) —> PbI2(s) + 2K+ (aq) + 2NO3- (aq) The net ionic equation is Pb2+ (aq) + 2I- (aq) —> PbI2 (s) 4. By mixing sodium carbonate, Na2CO3 (aq), with hydrochloric acid, 2HCl (aq), a bubbly, fizzy and clear precipitate is observed due to the formation of H2CO3 (s) which is insoluble according to the solubility rule. The reaction can be written as Na2CO3 (aq) + 2HCl (aq) —> H2CO3 (s) + 2NaCl (aq) The ionic for the equation is 2Na+ (aq) + CO3-2 (aq) + 2H+ (aq) + 2Cl- (aq) —> 2Na+ (aq) + 2Cl- (aq) + H2O (l) + CO2 (g) The net ionic equation is 2H+ (aq) + CO3-2 (aq) —> H2O (l) + CO2 (g)

5. By mixing sodium hydroxide, NaOH (aq), with hydrochloric acid, HCl (aq), no reaction precipitate is observed due to the formation of NaCl (aq) + H2O (l) which is soluble according to the solubility rule. The reaction can be written as NaOH (aq) + HCl (aq) —> NaCl (aq) + H2O (l) (Nothing). The ionic for the equation is Na+ (aq) + OH- (aq) + H+ (aq) + Cl- (aq) —> Na+ (aq) + Cl- (aq) + H2O (l) The net ionic equation is H+ (aq) + OH- (aq) —> H2O (l) 6. By mixing barium chloride, BaCl2 (aq), with sodium carbonate, Na2CO3 (aq) a cloudy, thick white precipitate is observed due to the formation of BaCO3 (s) which is insoluble according to the solubility rule. The reaction can be written as BaCl2 (aq) + Na2CO3 (aq) —> BaCO3 (s) + 2NaCl (aq) The ionic for the equation is Ba2+ (aq) + 2Cl- (aq) + 2Na+ (aq) + CO3-2 (aq) —> BaCO3 (s) + 2Na+ (aq) + 2Cl- (aq) The net ionic equation is Ba2+ (aq) + CO3-2 (aq) —> BaCO3 (s) 7. By mixing sodium hydroxide, NaOH (aq), with acetic acid, HC2H3O2 (aq), no reaction precipitate is observed due to the formation of NaC2H3O2 (aq) which is soluble according to the solubility rule. The reaction can be written as NaOH (aq) + HCl2H3O2 (aq) —> NaC2H3O2 (aq) + H2O (l) (Nothing).

The ionic for the equation is Na+ (aq) + OH- (aq) + H+ (aq) + C2H3O2- (aq) —> Na+ (aq) + C2H3O2- (aq) + H2O (l) The net ionic equation is H+ (aq) + OH- (aq) —> H2O (l) 8. By mixing sodium hydroxide, NaOH (aq), with ammonium chloride, NH4Cl (aq), no reaction but a foul odor precipitate is observed due to the formation of NaOH (aq) + NH4Cl (aq) which is soluble according to the solubility rule. The reaction can be written as NaOH (aq) + NH4Cl (aq) (nothing). The ionic for the equation is Na+ (aq) + OH- (aq) + NH4+ (aq) + C- (aq) The net ionic equation is OH- (aq) + NH4+ (aq) —> NH3 (aq) + H2O (aq) 9. By mixing ammonium chloride, NH4Cl (aq), with silver nitrate, Ag(NO3)2 (aq), no reaction precipitate is observed due to the formation of AgCl2 (s) which is insoluble according to the solubility rule. The reaction can be written as NH4Cl (aq) + Ag(NO3)2 (aq) —> AgCl2 (s) + 2NH4NO3 (aq) (nothing). The ionic for the equation is NH4+ (aq) + Cl- (aq) + Ag+ (aq) + NO3- (aq) —> AgCl (s) + NH4+ (aq) + NO3- (aq) The net ionic equation is OH- (aq) + NH4+ (aq) —> NH3 (aq) + H2O (l)

10. By mixing sodium sulfide, Na2S (aq), with hydrochloric acid, 2HCl (aq), a white and foul odor precipitate is observed due to the formation of 2H2S (s) which is insoluble according to the solubility rule. The reaction can be written as NaS2 (aq) + 2HCl (aq) —> 2H2S (s) + 7NaCl (aq) The ionic for the equation is 2Na+ (aq) + S-2 (aq) + 2H+ (aq) + 2Cl- (aq) —> 2Na+ (aq) + 2Cl- (aq) + H2S (g) The net ionic equation is 2H+ (aq) + S-2 (aq) —> H2S (g) 11. By mixing copper (II) sulfate, CuSO4 (aq), with sodium hydroxide, 2NaOH (aq), a cloudy, blue precipitate is observed due to the formation of Cu(OH)2 (s) which is insoluble according to the solubility rule. The reaction can be written as CuSO4 (aq) + 2NaOH (aq) —> Cu(OH)2 (s) + Na2SO4 (aq) The ionic for the equation is Cu+2 (aq) + SO4-2 (aq) + 2Na+ (aq) + 2OH- (aq) —> Cu(OH2) (s) + 2Na+ (aq) + SO4-2 (aq) The net ionic equation is Cu+2 (aq) + 2OH- (aq) —> Cu(OH)2 (s) 12. By mixing lead (II) nitrate, Pb(NO3)2 (aq), with potassium chromate, K2CrO3 (aq), a bright yellow precipitate is observed due to the formation of PbCO3 (s) which is insoluble according to the solubility rule. The reaction can be written as Pb(NO3)2 (aq) + K2CrO3 (aq) —> PbCO3 (s) + 2KNO3 (aq)

The ionic for the equation is Pb+2 (aq) + 2NO3- (aq) + 2K+ (aq) + CrO4-2 (aq) —> PbCrO4 (s) + 2K+ (aq) + 2NO3- (aq) The net ionic equation is Pb+2 (aq) + CrO4-2 (aq) —> PbCrO4 (s) 13. By mixing iron (III) nitrate, Fe(NO3)3 (aq), with sodium hydroxide, 3NaOH (aq), a dark orange and brown precipitate is observed due to the formation of Fe(OH)3 (s) which is insoluble according to the solubility rule. The reaction can be written as Fe(NO3)3 (aq) + 3NaOH (aq) —> Fe(OH)3 (s) + 3NaNO3 (aq) The ionic for the equation is Fe+3 (aq) + 3NO3- (aq) + 3Na+ (aq) + 3OH- (aq) —> Fe(OH)3 (s) + 3Na+ (aq) + 3NO3- (aq) The net ionic equation is Fe+3 (aq) + 3OH- (aq) —> Fe(OH)3 (s) 14. By mixing silver nitrate, Ag(NO3)2 (aq), with sodium hydroxide, NaOH (aq), a dark brown precipitate is observed due to the formation of Ag(OH)2 (s) which is insoluble according to the solubility rule. The reaction can be written as Ag(NO3)2 (aq) + NaOH (aq) —> Ag(OH)2 (s) + 2NaNO3 (aq) The ionic for the equation is Ag+ (aq) + NO3- (aq) + Na+ (aq) + OH- (aq) —> AgOH (s) + Na+ (aq) + NO3- (aq) The net ionic equation is Ag+ (aq) + OH- (aq) —> AgOH (s)

15. By mixing sodium chloride, NaCl (aq), with calcium nitrate, Ca(NO3)2 (aq), no reaction precipitate is observed due to the formation of BaSO4 (s) which is insoluble according to the solubility rule. The reaction can be written as 2NaCl (aq) + 2Ca(NO3)2 (aq) —> 2NaNO3 (aq) + 2CaCl2 (aq) (nothing). The ionic for the equation is 2Na+ (aq) Cl- (aq) + Ca+2 (aq) (NO3)2-2 (aq) —> 2Na+ (aq) NO3- (aq) + Ca+2 (aq) Cl2-2 (aq) The net ionic equation is Cl- (aq) + (NO3)2-2 (aq) —> NO3- (aq) + Cl2-2 (aq)

RESULTS AND DISCUSSION The purpose of this experiment was to determine whether or not the solutions were soluble or insoluble by referring to the solubility rules. Moreover, the solutions' reactions varied when it came to mixing different compounds together, which could have affected their precipitations. Therefore, most of the reactions were soluble because of the strong electrolytes in the elements and compounds such as their aqueous solutions. Thus, most reactions had a strong molecular, complete ionic, and net ionic equation during the process of precipitations.

During the experiment, some of the solutions did not change their colors, which was considered insoluble. However, that did not mean that there was no reaction, some of the solutions that were insoluble had fizzy, bubbly and foul odor. Furthermore, it probably had to with their ions that caused weak electrolytes and equations. As a result, certain aqueous solutions could not precipitate well; thus, the equations were labeled as spectator ions. POST LAB QUESTIONS 1. A) CaCO3 I B) Al(OH)3 S C) Hg2Cl2 I D) Pb(NO3)2 S 2. The precipitation reaction will occur when aqueous solutions of ammonium sulfate ((NH4)2SO4 (aq)) and calcium acetate (C4H6O4Cu (aq)) are mixed. Net Ionic Equation: 2NH4+ (aq) + SO4-2 (aq) + Ca+2 + C2H3O2- (aq) —> 2NH4+ (aq) + 2C2H3O2- (aq) + CaSO4 (s) 3. A reaction will occur with potassium chromate and silver nitrate. Balanced Molecular Equation: K2CrO4 (aq) + 2AgNO3 (aq) —> Ag2CrO4 (s) + 2KNO3 (aq) Ionic Equation: 2K+ (aq) + CrO4-2 (aq) + 2Ag+ (aq) + 2NO3- (aq) —> Ag2CrO4 (s) + 2K+ (aq) + 2NO3- (aq) Net Ionic Equation: 2Ag+ (aq) + CrO4-2 (aq) —> Ag2CrO4 (s) Spectator Ions: 2K+ and 2NO3-.

4. A) Pb(NO3)2 (aq) + Fe2(SO4)3 (aq) —> 3Pb(SO4) (s) + 2Fe(SO3)3 (aq) 3Pb+2 (aq) + 6NO3- (aq) + 2Fe+3 (aq) + 3SO4-2 (aq) —> 3Pb(SO4) (s) + 2Fe+3 (aq) + 6NO3(aq) 3Pb+2 (aq) + 3SO4-2 (aq) —> 3Pb(SO4) (s) B) Ni(OH)2 (s) + (NH4)2SO4 (aq) —> 2NH4OH (aq) + NiSO4 (aq) 5. A) 3CoCl2 (aq) + 2Cs3PO4 (aq) —> CO3(PO4)2 (s) + 6CsCl (aq) 3Co2+ (aq) + 6Cl- (aq) + 6Cs+ (aq) + 2PO4-3 (aq) —> Co3(PO4)2 (s) + 6Cs+ (aq) + 6Cl- (aq) 3Co2+ (aq) + 2PO4-3 (aq) —> Co3(PO4)2 (s) + 6Cl- (aq) Spectator Ions: 6Cl- (aq) and 6Cs+ (aq). B) 2Na3PO4 (aq) + 3CaCl2 (aq) —> 6NaCl (aq) + Ca3(PO4)2 (s) 6Na+ (aq) + 2PO4-3 (aq) + 3Ca+2 (aq) + 6Cl- (aq) —> 6Na+ (aq) + 6Cl- (aq) + Ca3(PO4)2 (s) 2PO4-3 (aq) + 3Ca+2 (aq) —> Ca3(PO4)2 (s) Spectator Ions: 6Na+ and 6Cl-....