Chemical Kinetics – Class 12 Chemistry Notes | CBSE NCERT Based

 📚 Chapter: Chemical Kinetics – Class 12 Chemistry Notes

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🔸 1. Introduction to Chemical Kinetics

Deals with the rate of chemical reactions and factors affecting them.

Tells us how fast a reaction occurs, and what mechanism it follows.

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🔹 2. Rate of Reaction

Average Rate = ΔConcentration / ΔTime

Instantaneous Rate = Rate at a particular moment

Units: mol L⁻¹ s⁻¹

For a reaction:

A → B

Rate = –d[A]/dt = +d[B]/dt

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🔹 3. Factors Affecting Rate

Concentration – ↑ Conc = ↑ Rate

Temperature – ↑ Temp = ↑ Rate (Arrhenius Eq.)

Catalyst – Alters rate without being consumed

Surface Area – ↑ Area = ↑ Rate

Nature of Reactants

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🔹 4. Rate Law and Order of Reaction

For reaction:

aA + bB → Products

Rate law:

Rate = k[A]^x[B]^y

x, y = Order w.r.t A, B

Overall order = x + y

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🔹 5. Molecularity vs Order

Molecularity Order

Theoretical concept Experimental

Can’t be zero Can be zero

Only whole numbers Can be fractional

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🔹 6. Integrated Rate Laws

Zero Order:

Rate = k

[A] = [A]₀ – kt

Unit: mol L⁻¹ s⁻¹

Straight line: [A] vs time

First Order:

Rate = k[A]

ln[A] = ln[A]₀ – kt

t½ = 0.693 / k

Unit: s⁻¹

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🔹 7. Arrhenius Equation

k = Ae^(–Ea/RT)

Where:

A = Frequency factor

Ea = Activation energy

R = Gas constant

T = Temperature (K)

Graph:

ln k vs 1/T → Straight line

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📌 Conclusion:

Chemical kinetics helps in understanding how and why a reaction proceeds at a certain rate. It’s crucial in designing industrial reactio

ns, drug manufacturing, etc.

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✍️ Written by: Shahid – Study with Shahid

🔗 Visit: https://shahidnotes12.blogspot.com