PART 7-Oxidation Reduction Reference: Chapter 11 in the textbook
PART 7 – Oxidation & Reduction Oxidation & Reduction Reference: Chapter 11 in the textbook Reference: Chapter 11 in the textbook 1
Oxidation number Oxidation number or oxidation state Definition In a compound the charge of each element would have if all shared e- pairs in the lewis structure were transferred to the more electronegative atom e.g. HCL, Co, CO2, H2O, Cl2, P4, Cao, Distinguish between the Oxidation Number and the Formal charge e.g. HCl, CO, cO2
Oxidation Numbe r z O da o u be o O da o S a e xidati on N u mber or Oxidati on S t a t e: Definition: In a compound, the charge of each element would have if all shared e- pairs in the Lewis Structure were transferred to the more electrone gative atom. e.g. HCl, CO, CO 2, H 2O, Cl 2, P 4, CaO, … z Distinguish between the Oxidation Number and the Formal Charge e g HCl CO CO e.g. HCl, CO, CO 2, … 2
Rules for Assigning Oxidation (Ref: textbook, pg. 393): Be applied in order o Sum of all atoms' oxidation #s in a compound must equal to its net charge 2 Elementary substance (all the same atom):=0 3 In a compound: Group IA=+1; Group lIA=+2 B Al are +3: Fis-1 4 In a compound: H is +1; except in MH where H is-1 ⑤ In a compound:Ois-2 3
Rules for Assig g nin Oxidation # z ( pg ) pp Ref: textbook, pg. 393): Be applied in order: ① Sum of all atoms Sum of all atoms’ oxidation #s in a compound must oxidation #s in a compound must equal to its net charge. ② Elementary substance (all the same atom): = 0 ③ I d G IA 1 G IIA 2 In a compound: Group IA = +1; Group IIA = +2; B, Al are +3; F is -1. ④ In a compound: H is +1; except in MH where H is -1. ⑤ In a compound: O is -2. 3
Oxidation number Periodic Table Oxidation number: related to an atoms valence electrons Highest possible oxidation number of its valence electrons LoWest possible oxidation number #f of electrons needed to gain for an octet Example: C(Group IVA:+4, -4): N(Group VA: +5, -3) s( GroupⅥA:+6,-2);Cl( GroupⅦA:+7,-1) 4
Oxidation Number & Periodic Table z Oxidation number: related to an atom’s valence electrons Highest possible oxidation number: Highest possible oxidation number: = # of its valence electrons Lowest possible oxidation number: = # of electrons needed to gain for an octet z Example: C (Group IVA: +4, -4); N (Group VA: +5, -3); S (Group VIA: +6, -2); Cl (Group VIIA: +7, -1). 4
Practice Assigning the oxidation number of each elements in the following compounds (a) CaCao (b)H2S46 (c)V2 d)OF (e)Ncl3 f) sbH (g) socl2
Practice z Ass g g e o da o u be o eac igning the oxidation number of each elements in the following compounds: ( )C CO (a) CaCrO4 (b) H2S4O6 ( ) 2 (c) VO2+ (d) OF2 (e) NCl (e) NCl3 (f) SbH3 (g) SOCl2 5