Lecture 14 precipacid base RH acid base examples

Acid Base chemistry - general examples

1. Writing Precipitation Reactions Pb (NO 3 ) 2 ( aq ) + 2NaI ( aq ) → PbI 2 ( s ) + 2NaNO 3 ( aq ) Pb 2+ ( aq ) + 2NO 3 - ( aq ) + 2Na + ( aq ) + 2I - ( aq ) → PbI 2 ( s ) + 2Na + ( aq ) + 2NO 3 - ( aq ) Pb 2+ ( aq ) + 2I - ( aq ) → PbI 2 ( s ) Complete Ionic Equation Net Ionic Equation Intact-compound Equation

2. Solubility Rules

3. Acid-Base Reactions When an acid and a base are mixed, they react to make water and a salt This is an acid-base neutralization reaction HCl + NaOH → H 2 O + NaCl

4. How to calculate oxidation state Rules are hierarchical – If any two conflict, follow the rule that is higher on the list Substances with one type of atom (H 2 , O 2 , S 8 , C 60 , Ca (s) , Ca 2+ ( aq ) , Cl – Mo 6+ ( aq ) , Mo (s) , Au 3+ ( aq ) , Au (s) ) have the same oxidation state as their charge. (0 if no charge) O is -2 (unless O 2 or H 2 O 2 ) H is +1 (unless H 2 ) IA elements are typically +1 IIA elements are typically +2 Halogen elements are typically -1 Follow table Sum of all oxidation states in a compound must equal the overall charge of the molecule  

5. Practice Determining Oxidation State H 2 O 2 Fe 2 O 3 MnO 4 - CH 2 O NaClO 4

6. OIL RIG O xidation I s L oss of e - R eduction I s G ain of e - Reducing agents get oxidized Oxidizing agents get reduced Nomenclature of Redox Reactions http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2014/1/13/1389639256785/North-Sea-oil-rig-012.jpg

7. More Practice !! ( aq ) + H 2 (g)   MnO 2 + 4 HCl → MnCl 2 + Cl 2 + 2 H 2 O

8. Electromotive Force Series All metals tend to lose electrons Some have a higher tendency Zn 2+ + Mg → Zn + Mg 2+ Zn + Mg 2+ → Zn 2+ + Mg Electron Movement

9. Electricity! If we isolate the two metals, we can make the electrons flow through a wire Zn + Cu 2+ → Zn 2+ + Cu Zn → Zn 2+ Cu 2+ + 2 e - → Cu + 2 e - Cu 2+ → Cu Electron Movement

10. Question Question A battery is made of iron and aluminum electrodes. What equation best represents the redox reaction that occurs? Al 2+ + Fe 2+ → Al + Fe Al 2+ + Fe → Fe + Al Al 2+ + Fe → Fe 2+ + Al Al + Fe 2+ → Fe + Al 2+ http://phillypaws.org/1-month-150-lives-3rd-annual-paws-foster-challenge/

11. Wet Cell Lead Acid Battery 2 SO 4 ( aq )   2 volts per cell

12. Dry Cell Alkaline Battery     Zn Insulator 1.5 volts per cell