Redox reactions Flashcards
Define Oxidation
- gain of oxygen or electronegativity element
- Loss of elements
- Increase in O.S
- Loss of hydrogen or electropositive element
Define Reduction
- loss of oxygen or electronegativity element
- gain of elements
- decrease in O.S
- gain of hydrogen or electropositive element
What is oxidation number ?
denotation of oxidation state in a compound of a given element
What are the rules for oxidation number?
- Alkali metals = +1
Alkali earth metals = +2 - Oxygen = -2
peroxide = -1
superoxide = +1 - Hydrogen =+1
with metals =-1 - Florine = -1
- Sum of all O.S = 0 in compounds
Sum of all O.S = Charge in ions
How can you find the highest O.S of any compound?
Group number - 10
What is/are the conditions for an combination reaction to be a redox reaction?
For a reaction to be combination as well as redox at least one of the element need to be in their elemental state
How is decomposition reaction different from combination reaction
Decomposition reaction involves in breaking down of compounds. It Produced an elemental compound
Combination is the formation of compound from one or more elemental compound
Define displacement reaction
Displacement reaction replacement of ions or atoms in the compound to form a new compound
1. metal displacement
2. Non-metals displacement
Why does F not show disproportionation reaction?
F doesn’t show disproportionation reaction because it has only one oxidation state that is -1
What is disproportionation reaction?
disproportionation reaction is where the same element undergoes oxidation are reduction at the same time
H2O2 = H2 = O2
What is the oxidation state for the following molecules
1. S in H2S4O6
2. Br in Br3O8
3. O in H2O2
4. O in HO2F
5. S in H2SO5
6. Cr in CrO5
- +5,0
- +6,+4
- -1
- -1,+1
- +6
- +6
How to balance redox reaction with half electron method?
- identify oxidation and reduction half reaction
- Balance all other atoms
- Balance O by adding H20
- Balance H by adding H+
- Balance the charge by adding electron
- All the reaction (make sure that he electrons get canceled )
- Add OH- on both sides for basic medium
no of OH- = no of H+
How to balance redox reaction with oxidation number method?
- identify oxidation and reduction reaction
2.Balance the charge - Balance all other atoms
- Balance O by adding H20
- Balance H by adding H+
- Add OH- on both sides for basic medium
no of OH- = no of H+
What are the application of Redox reaction?
There are two applications of redox reaction :
1. Titration
2. Cells
How is redox reaction used in Titration?
It can used to find the end point of the reaction:
1. Self indicators : like MnO4- tell the end point by losing their colour
2.The solution getting coloured by getting colour at end point like Cr2O7-
3. Use of I- in the reaction that gives a dark Blue colour
