Learn Chemistry with Prof. Kiran Patil

Ion electron method (Half reaction method) Step I: Write unbalanced equation for the redox reaction, Assign oxidation number to all the atoms in the reactants and products. Divide the equation into two half equations. One half equation invoolves increase in oxidation number and anonumber (Write two half equation separately)  Step II: Balance the atoms except O and H in each half equation. Balance oxygen atom by adding H.O to the side with less O atoms. Step III: Balance the H atom by adding H ions to the side with less H atoms. Step IV: Balance the charges by adding appropriate number of electrons to the right side of oxidation half equation and to the left of reduction half equation. Step V: Multiply half equation by suitable factors to equalize the number of electrons in two half equations. Add two half equations and cancel the number of electrons on both sides of equation. Step VI: If the reaction occurs in basic medium then add OH ions, equal to number of H+ ions on...

  The Oxidation number method is illustrated in the following steps: Step 1: Write the unbalanced equation for redox reaction. Balance the equation for all atoms in the reactions, except H and O. Identify the atoms which undergo change in oxidation number and by how much. Draw the bracket to connect atoms of the elements that changes the oxidation number. Step II: Show an increase in oxidation number per atom of the oxidised species and hence the net increase in oxidation number. Similarly show a decrease in the oxidation number per atom of the reduced species and the net decrease in oxidation number. Determine the factors which will make the total increase and decrease equal. Insert the coefficients into the equation. Step III: Balance oxygen atoms by adding H.O to the side containing less O atoms, One HO is added for one O atom. Balance H atoms by adding H ions to the side having less H atoms. Step IV: If the reaction occurs in basic medium, then add OH ions, equal to the number ...

Key Points Oxidant / oxidizing agent: A reagent / substance which itself undergoes reduction and causes oxidation of another species is called oxidant or oxidizing agent This is an electron acceptor. Reductant / Reducing agent: A reagent reducing agent is defined as a substance reagent which itself undergoes oxidation and brings about reduction of another species. A reductant is electron donor. Displacement reactions : can also be looked upon as redox reactions. In such reactions an ion (or atom) in a compound is replaced by an ion (or on atom) of another element. X+YZ-XZ+Y Cu+znso4 ----› znso4+Cu

Key Points  Oxidation it is defined as: a. addition of oxygen. b. addition of electronegative element. c. removal of hydrogen. d. removal of electropositive element. e. loss of electrons by any species. Reduction it is defined as a. removal of oxygen. b. removal of electronegative element. c. addition of hydrogen. d. addition of electropositive element. e. Gain of electrons by any species..