chemistry-class-12-unit-05-chapter-05-surface-chemistry-l-5-6-1usef0iypy4

Surface chemistry
Lecture-5

Surface chemistry Lecture-5

Surface chemistry

logA Vs $E^{cat}_a$
$k^{cat}$ = $A^{cat}$ $e^-{\frac{E^{cat}_a}{RT}}$
$k^{uncat}=A^{uncat}$ $e^-{\frac{E^{uncat}_a}{RT}}$
Zeolite catalysts - $SiO^{4-}_4$ , $AlO^{5-}_4$
Lewis and bronsted
Enzyme catalysis

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Surface chemistry

What is common amongst

Smoke
Homogenized milk
Shampoo COLLOIDS/EMULSIONS

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Colloids

What is a colloid ?

Thomas Graham 1851 - diffusion of gases

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Colloids

Colloidal chemistry is Wolfgang Ostwald “world of neglected dimensions”
Chemistry of grains , Drops , bubbles , filaments and films
Chemistry of everyday life solution

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Colloids

It has two components

1.) Dispersed phase

continuous / dispersion phase

Emulsifying agent

2.) Dispersion medium

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Types of colloids

Dispersed phase	Dispersion medium	Name	Examples
Liquid	Gas	Liquid aerosol	Fog
Solid	Gas	Solid aerosol	Smoke
Gas	Liquid	Foam	Soda
Liquid	Liquid	Emulsion	Milk
Solid	Liquid	Sol	Toothpaste
Gas	Solid	Solid foam	Pumice
Liquid	Solid	Solid emulsion	Pearl
Solid	Solid	Solid sol	Ruby glass

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Many processes involve colloidal phenomena

Adhesion
Detergency
Road surfacing
Electrophoretic deposition
Sewage disposal
Emulsion polymerisation

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Many processes involve colloidal phenomena

Soil conditioning
Food processing
Sugar refining
Lubrication wetting
Oil - well drilling

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Common colloids

Aerosols
Agrochemicals
Cement
Cosmetics
Dyestuffs
Emulsions

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Common colloids

Fabrics
Foams
Foodstuffs
Ink
Paint

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Common colloids

Paper
Pharmaceuticals
Plastics
Rubber
Soil

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

\rightarrow

Preparation of colloids

Surface chemistry Lecture-5

Differences between colloids and classical chemistry

Classical Chemistry	Colloids
Limited size particles	10000- $10^8$
Freezing point lowering	FP lowering undetectable
Solutions clear	Solutions turbid
Particle diffusion seen	Diffusion undetectable
Ions with small charge	Highly charged
Molecules “spherical”	Shape dissymmetry
Limited flexibility	Flexible

Surface chemistry

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Colloids

\rightarrow

Types of colloids

\rightarrow

Many processes involve colloidal phenomena

\rightarrow

Common colloids

\rightarrow

Differences between colloids and classical chemistry

\rightarrow

Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Properties of colloids

(1) Optical

(2) Kinetic

(3) Stability

(1) Optical - dust particles scattering light tyndall effect

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

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Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Properties of colloids

Tyndall effect - colloidal optical property
Zsigmondy 1909 - ultramicroscopy

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

\rightarrow

Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

\rightarrow

Preparation of colloids

Surface chemistry Lecture-5

Properties of colloids

Kinetic

Diffusion
Brownian
Dialysis
Electrokinetic

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

\rightarrow

Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

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Preparation of colloids

Surface chemistry Lecture-5

Properties of colloids

Electrokinetic

Electrophoresis
Electro - osmosis
Streaming potential

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

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Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

\rightarrow

Preparation of colloids

Surface chemistry Lecture-5

Dialysis - Thomes Gochan

Kidney dialysis to semi permeable membrane

[Urea/creatines $\rightarrow$ urine]

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

\rightarrow

Differences between colloids and classical chemistry

\rightarrow

Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

\rightarrow

Preparation of colloids

Surface chemistry Lecture-5

Preparation of colloids

Condansation (Bottom - up)
Dispersion(Top - down)

(1) $FeCl_3$ $H_2O$ $100^oC$ $Fe(OH)_3$

(2) $AuCl_4 + 4 Au ~$

$Au^0$

Surface chemistry

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Colloids

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Types of colloids

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Many processes involve colloidal phenomena

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Common colloids

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Differences between colloids and classical chemistry

\rightarrow

Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

\rightarrow

Preparation of colloids

Surface chemistry Lecture-5

Preparation of colloids

$AgI \left[Ag^+\right]=\left[I\right]=10^{-8}$

$KI+AgNO_3 \rightarrow AgI$

$AgNO_3$

Surface chemistry

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Colloids

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Types of colloids

\rightarrow

Many processes involve colloidal phenomena

\rightarrow

Common colloids

\rightarrow

Differences between colloids and classical chemistry

\rightarrow

Properties of colloids

\rightarrow

Dialysis - Thomes Gochan

\rightarrow

Preparation of colloids

Thank you

Surface chemistry Lecture-5