1. Chemical Reactions What’s in the Bottles?

2. What’s in the Bottles Qualitative Analysis –Identification –Not quantitation –Volumes of reagents not critical A basic understanding of double- displacement reactions important

3. Evidences of a Chemical Reaction Color change Precipitate formation Temperature change Gas evolution Formation of a weak electrolyte

4. Solubility Rules (abbreviated list) Group 1 compounds are soluble All nitrates are soluble Most chlorides are soluble –Exceptions are Pb 2+, Ag +, Hg 2 2+ Most sulfates are soluble –Exceptions are Sr, Ba, Pb, Hg 2 2+ Refer to Lab Manual Appendix 4 for more complete list

5. KNO 3 (aq)   K + (aq) + NO 3 - (aq) Cu(NO 3 ) 2 (aq)   Cu 2+ (aq) + 2 NO 3 - (aq) Solubility Reactions H2OH2O H2OH2O

6. 3 Representations of Chemical Equations Whole molecular equation Pb(NO 3 ) 2 (aq) + 2 KI (aq)   PbI 2 (s) + 2 KNO 3 (aq) Whole ionic equation Pb 2+ (aq) + 2 NO 3 - (aq) + 2 K + (aq) + 2 I - (aq)   PbI 2 (s) + 2 K + (aq) + 2NO 3 - (aq) Net ionic equation Pb 2+ (aq) + 2 I - (aq)   PbI 2 (s) Whole molecular equation Pb(NO 3 ) 2 (aq) + 2 KI (aq)   PbI 2 (s) + 2 KNO 3 (aq) Whole ionic equation Pb 2+ (aq) + 2 NO 3 - (aq) + 2 K + (aq) + 2 I - (aq)   PbI 2 (s) + 2 K + (aq) + 2NO 3 - (aq) Net ionic equation Remove the spectator ions Whole molecular equation Pb(NO 3 ) 2 (aq) + 2 KI (aq)   PbI 2 (s) + 2 KNO 3 (aq) Whole ionic equation Pb 2+ (aq) + 2 NO 3 - (aq) + 2 K + (aq) + 2 I - (aq)   PbI 2 (s) + 2 K + (aq) + 2NO 3 - (aq) Net ionic equation Pb 2+ (aq) + 2 I - (aq)   PbI 2 (s)

7. Some notes about this week’s lab Concentrated acids: BE CAREFUL AgNO 3 will stain your skin—wear gloves All waste must be collected in designated containers Use well plates One pipette per bottle please! Test for temperature change if no other indications Determine unknowns BEFORE leaving lab

8. Some notes about this week’s lab Litmus Paper: Base turns red paper blue Acid turns blue paper red Note: use a glass stir rod to spot the litmus paper—DO NOT dip litmus into solution D Aci Re B ase lue Cute, huh?

9. Some Example Reactions Whole molecular reaction ( Double-Displacement ) 2 AgNO 3(aq) + ZnCl 2(aq)  + 2 AgClZn(NO 3 ) 2 Will a reaction occur? Write possible products. Will a precipitate form? Check the solubility rules. (aq)(s)

10. Some Example Reactions Reagents AgNO 3 Ba(NO 3 ) 2 NaOHHCl AgNO 3 Ba(NO 3 ) 2 NaOH HCl Brown Solid White Solid NR Temp Increase

11. Some notes about groups and reports  Group Dynamics  It is each members responsibility to make sure that ALL group members understand the material  Play well with others!

12. Some notes about groups and reports This investigation, Author 1: Introduction and Conclusion 2: Discussion 3: Data/Results and Experimental This investigation, Author B: Introduction, Conclusion, Data/Results A: Discussion and Experimental

13. Procedure Design Today With your group you should develop a procedure that will allow you to determine which set of bottles you have been assigned. You must create complete reaction tables (chemical equations with expected products, if any) for 2 of the possible groups (you choose which two). Note: You must complete the ID of the bottle group assigned before leaving lab.

15. Exit Quiz There is no exit quiz this week Have a great week!