Redox Reactions Mind Maps PDF

PHYSICS...

PHYSICS OXIDISING AGENT OXIDATION BALANCING OF REDOX REACTIONS (OXIDANTS): NUMBER REDOX REACTION WALLAH A reagent which can increase RULES TO ASSIGN OXIDATION NUMBER the oxidation 1) Identify oxidation and reduction 1) Oxidation number of an element in free elemental number. REDUCING AGENT 2) Make total increase and total decrease state or Uncombined state zero (REDUCTANTS): in O.N equal 2) In polyatomic ion, the algebraic sum of all the oxidation numbers of atoms of the ion must equal OXIDATION: A reagent which REDOX REACTIONS: 3) Balance atoms except O & H the charge on the ion Increase in the can decrease Reactions which 4) the oxidation ACIDIC BASIC 3) The oxidation number of oxygen in most oxidation number involve change number. Balance Balance of the compounds is -2 in oxidation number In peroxides -1 - Oxygen with H2O - Charge with OH- REDUCTION: of the In superoxides -1/2 In O2 F2 +1 Decrease in the interacting species - Hydrogen with H+ - Oxygen with H2O In OF2 +2 oxidation number 4) Oxidation number of hydrogen is +1 in most of its compounds(In metal hydrides -1) 5) Oxidation number of fluorine is always -1 in its compounds 6) Alkali metals have oxidation number +1 and alkaline earth metals have oxidation number +2 always in its compounds REDOX REACTION 7) The algebraic sum of the oxidation number of all the atoms in a compound must be zero. TYPES OF REDOX REACTIONS > +1 x -2 KMnO4 1 + x + 4x(-2) = 0 x = +7 DECOMPOSITION REACTION DISPLACEMENT REACTION DISPROPORTIONATION REACTIONS COMBINATION REACTION Reaction leads to the breakdown of a An ion (or an atom) in a compound In a disproportionation reaction an element POINTS TO A redox reaction in the form compound into two or more components is replaced by an ion (or an atom) of in one oxidation state is simultaneously REMEMBER A+B→C at least one of which must be in the another element. oxidised and reduced. Either A and B or both A and B must be in elemental state. X + YZ → XZ + Y It always contains an element that can exist the elemental form for such a reaction to be eg: H2O → H2 + O2 Fe3O4 in at least three oxidation states. Carbon suboxide CaOCl2 a redox reaction. +2 O +2 +2 +3 +1 -1 eg: 2H2O2 → 2H2O + O2 O = C = C = C = O FeO. Fe2O3 Ca(OCl)Cl eg: H2 + Cl2 → 2HCl Comproportionation reaction: CrO5 Tribromooctaoxide A reaction in which an element in a -2 O higher oxidation state reacts with the -1 O O O -1 O same element in a lower oxidation state to = = = = = = O +6 +4 +6 O= Br Br =O Cr Br give the element in an intermediate O -1 +6 O-1 O O O oxidation state METAL NON-METAL eg: Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O DISPLACEMENT DISPLACEMENT Tetrathionate ion A metal in a compound can be Non-metal in a compound can O O Highest O.S— Undergoes Reduction—Oxidising agent displaced by another metal in be displaced by a metal or a - O S +5 O S O S S +5 O - the uncombined state. non-metal Lowest O.S — Undergoes Oxidation—Reducing agent eg: CuSO4 + Zn → Cu + ZnSO4 eg: Zn + H2SO4 → ZnSO4 + H2 O O Intermediate O.S — Oxidation & Reduction Na + H2O → NaOH + H2 —Oxidising Agent & Reducing Agent