Concept of Oxidation and Reduction

1 amu = 1.66 × 10×^-24 gm
amu = \frac{1}{12} \times \frac{12}{6\times10^{23}} = 0.166 \times 10^{-23}g
1 amu = \frac{1}{N_{A}}

Limiting reagent (L.R) :
The reactant of a reaction which reacts completely

According to balanced reactions
1 mole N₂ → 3mole H₂
2mole N₂ → 6 mole H₂
L.R = H₂
3 mole H₂ → 1mole N₂
5mole H₂ → 5/3 mole of N₂
mole of N₂ remained unreacted = 2 − 5/3
= 1/3

Mole of NH₃ formed :
3mole H₂ → 2mole of NH₃
5mole of H₂ → \frac{5 \times 2}{3} = \frac{10}{3} = 3.33

% of purity :

100 gram — 22.4
9 gram — \frac{9 \times 22.4}{100}
[Since wt of CaCO₃
\frac{10 \times 90}{100} = 9 \ gram]
\tt \% \ of \ purity = \frac{wt. of \ pure \ compound}{wt. of \ impure \ compound} \times 100

Oxidising agent (or) oxidant :
Which undergoes reduction i.e gain of e⁻

Reducing agent (or) reductant :
Which undergoes oxidation (or) which loses electron

Types of Redox Reactions :
Combination Reaction :

E.wt of 'C' = \frac{12}{4} = 3g
E.wt of 'O' = \frac{16}{2} = 8g

E.wt of Mg = \frac{24}{2} = 12g
E.wt of N_{2} = \frac{14}{3}g
Note : Neutralisation reactions are not redox reaction.

Decomposition reaction :

Displacement reactions :
Metal displacement reactions

Non - metal displacement reactions :
F₂ + 2KCl → 2KF + Cl₂
F₂ + 2KBr → 2KF + Br₂
F₂ + 2KI → 2KF + I₂

Disproportional reactions :
Note : {Halogen, P, S are disproportional}
In this reaction the same substance undergoes both oxidation and reduction.

Comproportional reactions :