Notes Sept 17 2013 Oxidation Reduction Reactions Oxidation Loss of electrons Reduction gain of electrons Keep track of oxidation number for individual atoms Oxidation numbers Atoms molecular elements in standard form 0 Ions oxidation number charge Common values H 1 Halogens Cl Br I 1 O 2 F 1 o Halogens are 1 except when attached to O or F where its 1 Molecule Sum of oxidation numbers 0 Complex ion Sum of oxidation numbers charge of ion ConcepTest Which oxidation numbers are correct for the indicated atom i oxygen in O2 ON 0 correct standard form ii oxygen in HO ON 1 wrong it s 2 iii oxygen in CO2 ON 2 A i only B ii only ON C i iii D i ii E ii iii F i ii iii C O2 CO2 0 0 4 2 ConcepTest Which elements get oxidized and reduced respectively in the equation 2 Fe2O3 s 3 C s 4 Fe s 3 CO2 g A iron oxygen B carbon iron Carbon 0 4 oxidation C carbon oxygen D iron carbon Iron 3 0 reduction ConcepTest For which reaction is an oxygen atom reduced and chlorine atom oxidized A 2 NaOCl F2 2 NaF Cl2 O2 1 2 1 0 1 1 0 0 O oxidized Cl reduced B Cl2 2 O2 2 ClO2 0 0 4 2 O reduced Cl oxidized C 2 NaCl O2 2 NaOCl 1 1 0 1 2 1 Cl oxidized O reduced D H2O2 2 NaCl Cl2 2 NaOH 1 1 1 1 0 1 2 1 O reduced Cl oxidized ConcepTest Which chemical reaction type best describes this reaction 2 AgNO3 aq Cu s 2 Ag s Cu NO3 2 aq A acid base B precipitation C gas forming D oxidation reduction Acid base make H make HO combine H HOPrecipitation A B C D both have to be aq partners switch Just because there is solid in the products doesn t mean that it is a precipitate Which chemical reaction type best describes this reaction CaO s H2O l Ca OH 2 s A acid base B precipitation C gas forming D oxidation reduction Not B because neither are ionic compounds aqueous solutions or swapping partners Not C because no gas is formed Not D because nothing is oxidized or reduced Metal oxides are basic CaO nonmetal oxides are acidic H2O Module 4 Stoichiometry Mass Relationships in Reactions Limiting Reagents Percent yield Chemical Analysis Concentration in Solution Molarity Acidic Concentration pH Stoichiometry in Solution Spectrophotometry 1 4 Masses Moles 5 7 Solutions ConcepTest WebAssign is A Serenity B four horsemen of apocalypse ConceptTest For reaction 4 NH3 5 O2 4 NO 6 H2O A 4 6 6 B 4 3 5 C 4 12 10 C Dante s inferno D Devil How many N H O D 4 5 4 6 E 4 4 5 ConcepTest For the reaction a N2 b O2 N2aO2b If 2 8 g of N2 yields 9 2 g of N2aO2b what are a and b respectively A 1 1 B 1 2 C 2 1 D 2 2 N2 2 8 g O2 6 4 g NO 9 2 g E need more info