Oxidation Number Change Method
Oxidation Number Change Method: Following steps are followed while balancing redox equation by this method: (i) Select the atom in oxidising agent whose oxidation number decreases and write the gain of electrons. (ii) Select the atom in reducing agent whose oxidation number increases and write the loss of electrons. (iii) Now cross multiply, i. e. , multiply oxidising agent by no. of loss of electrons and reducing agent by no. of gain of electrons. (iv) Balance the number of atom on both sides whose oxidation number change in the...
read moreIon-Electron Method
Ion-Electron Method for Balancing Redox Reaction: Following steps are followed while balancing redox equations by this method: (i) Split the complete equation into two half reactions, one representing oxidation and the other reduction reactions. (ii) Balance these equations with respect to charge by introducing electrons. (iii) Multiply half equations to equalize the number of electrons. (iv) Add the above equations to obtain an equation which is balanced with respect to charge an atom. ions may be placed according to the medium of the...
read moreCases of oxidation Number
Special Cases of Oxidation Number (1) : (2) (Caro’s is acid) (3) (Marshall’s acid) (4) : Oxidation number. of ‘S’ is +2 but oxidation state are -2 and + 6. (5) Oxidation number of ‘S’ is +5/2 or 2.5 however, oxidation state are Two ‘S’ –atoms 5 – each; Two ‘S’ – atoms 0 – each. (6) In (7) (8) Oxoanions are stronger oxidising agents in acidic medium in comparison to basic or neutral mediums. (9) In oxidation number of C-atom is...
read moreOxidising and Reducing Agent
Equivalent mass of Oxidising and Reducing Agent The equivalent mass of an oxidising and a reducing agent may be calculated by dividing the molecular mass of the oxidising or reducing agent by change in oxidation number in the reaction. Thus, For example: (i) has different equivalent masses in different mediums (acidic, alkaline and neutral). In acidic medium: Equivalent mass of In alkaline medium: Equivalent mass of In neutral medium: Equivalent mass of (ii) in acidic...
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A reaction in which both oxidation and reduction take place simultaneously is called redox (reduction + oxidation) reaction. E. g. (i) In this reaction Ox. No. of hydrogen increases from zero to +1 (oxidation) and that of sulphur decreases from zero to -2 (reduction). In this reaction hydrogen is reducing agent and S is oxidising agent. (ii) In this reaction Ox. No. of Fe increases from +2 to +3 (oxidation) and that of chlorine decreases from zero to (reduction). Hence is reducing agent and is oxidising agent. In this...
read moreOxidation Number
Oxidation number (Ox. No.) “It is the number of electrons of an atom of that element which has lost or gained in going from the free element in its natural state to its new state in that particular compound”. It is quite clear that oxidation state (number) implies the effective charge associated with an element. Hence it may be positive or negative. Positive oxidation number (Ox. No.) implies the number of electrons which must be added to a cation to give a neutral atom. Similarly, negative oxidation number means the number of...
read moreConcept of Oxidation and Reduction
Electronic Concept of Oxidation and Reduction (Modern Concept) The process in which any substance (atom, ion or molecule) loses one or more electrons is called oxidation. Thus, it is a deelectronation process. The substance which loses electrons is said to be oxidised. E. g. The above reactions are known as oxidation half-reactions. In these reactions are oxidised to, , respectively. The process in which any substance (atom, ion or molecule) gains one or more electrons is called reduction. Thus it is an electronation process. The...
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