Maharishi school of excellence

Senior secondary

Chemistry
investigatory project

“ANALYSIS ON SOAPS”

By:

Name: S. Dharanidharan
Grade: 11
Section: A
Roll.No: 11004
 Acknowledgement:-

Myself S. Dharanidharan studying in Grade 11, section-A, Maharishi

school of excellence, have taken this opportunity to express my respect
and gratitude towards my esteemed guide
Mrs. Anitha kumari, for her valuable guidance in making this project
a reality. I am thankful for her support and encouragement and
supervision, guidance and encouragement throughout this project
completion period.
 Table of contents:

1) Introduction to Soaps

2) Preparation of Soaps

3) Ph analysis

4) Properties of Soap

5) Tensile strength analysis

6) Chemical composition

7) Varieties of soaps

Introduction to Soaps :-
Soap, a seemingly ordinary household item, holds a fascinating place in a
whole of chemistry. At its ore, soap is a chemical compound resulting from
the remarkable interplay between fats or oils and strong alkaline
substances. This chemical synergy is responsible for soap’s exceptional
ability to cleanse and remove dirt from a variety of surfaces, particularly our
skin.

The history of soap dates back thousands of years, with early evidence of

Soap-making found in ancient Babylon around 2800 BC. These early

soaps were crude mixtures of animal fats and wood ash, primarily used for
cleaning textiles rather than personal hygiene.

The chemistry behind the soap’s cleaning process lies in its molecular
structure. Soap molecules consist of a hydrophilic(water-attracting) head
and a hydrophobic(water-repelling) tail. When soap is introduced to water
and dirt, its hydrophobic tails attach themselves to grease and grime, while
hydrophilic heads surround the dirt, creating micelles. These micelles are
easily rinsed away, carrying the dirt with them.

Furthermore, soap’s ability to alter the surface tension of water enhances

its cleaning power. This phenomenon enables the soap to break down
stubborn stains and oils, making it an indispensable part of our daily lifes.

Preparation of soaps:-
The creation of soap is a chemical artistry that transforms ordinary
ingredients into a remarkable cleansing agent. This process, known as
saponification, is deeply rooted in the realm of chemistry and been refined
over centuries.

The primary ingredients in soap-making are fats or oils and strong alkaline
substances, typically sodium hydroxide (NaOH) for solid soaps and
potassium hydroxide (KOH) for liquid soaps. The chemistry behind soap
production lies in the reaction between these ingredients, resulting in the
formation of soap molecules and a glycerol.

The first step in preparation of soap involves the selection of fats or oils.
Different oils yield different properties in the final soap, from hardness to
lather quality. Once chosen, these oils undergo a process called hydrolysis
when mixed with a alkali, breaking the ester bonds in triglyceride molecules
to release fatty acids and a glycerol.

The freed fatty acids then react with the alkali, creating soap molecules
through a chemical reaction known as saponification. This chemical
transformation gives soap its unique ability to bind both water and oil,
making it an ideal cleaning agent. The glycerol produced in the process in
a valuable byproduct often used in various industries.

In conclusion, the preparation of soaps is a testament to the power of

chemistry in everyday life.

pH analysis :-
pH analysis on soap is crucial to ensure its effectiveness and safety for
skin. Soap is a chemical compound formed by the reaction of a fatty acid
with an alkali. The pH scale measures the acidity or alkalinity of a
substance, ranging from 0 (highly acidic) to 14 (highly alkaline), with 7
being neutral.

Soap’s pH level is essential because it affects its cleansing properties and

skin compatibility. Ideally, soap should have a pH around 5.5. Soaps with

pH levels significantly higher or lower can disrupt the skin’s protective

barrier, leading to dryness, irritation, or even dermatitis.

To measure the pH of a soap, a pH meter or pH strip is used. The soap is

dissolved in distilled water, and the pH of the solution is measured. If pH of
soap falls around (5-7) it is safe a gentle for use.

Properties of soap:-
1. Surfactant:-

Soap is a surfactant, which means it reduces the surface tension of

water. This enables it to spread easily and penetrate surfaces, lifting
away dirt and oils.

2. Hydrophilic & hydrophobic:-

Soap molecules have a hydrophilic (water-attracting) and hydrophobic

Head and hydrophobic (water-repelling) tail. This dual nature allows
soap to interact with both water and oils, facilitating the removal of
grease and dirt from surfaces.

3.Emulsification:-

Soap can emulsify oils and fats, breaking them down into tiny droplets
that can be dispersed in water. This is essential for effective cleaning,
as it allows these substances to be washed away.

4.Foaming:-

Soap can create foam when agitated with water, trapping dirt and
impurities within bubbles, which are then rinsed away.

5. Alkaline Nature:-

Most soaps are mildly alkaline, which helps neutralize acidic substances
on surfaces. This makes soap effective for cleaning various materials.

6.Gentle on Skin:-
 Soap is generally gentle on the skin because it doesn't disrupt the skin's
natural pH balance. However, some harsh soaps can be drying to the
skin.

7. Biodegradable:-

Soap is biodegradable and environmentally friendly, as it can break

down into harmless substances in water.

8. Versatile:-

Soap can be used for various cleaning purposes, from washing hands
and dishes to cleaning fabrics and surfaces.

9. Antibacterial Properties:-

Some soaps may contain antibacterial agents to help kill or inhibit the
growth of bacteria, to cause no harm to the user.

10. Fragrance and Additives:-

Soaps can be formulated with fragrances, moisturizers, and other

additives to enhance their scent and skin-conditioning properties.

Tensile strength analysis:-

Tensile strength analysis of soap involves assessing its ability to withstand
stretching or pulling forces without breaking. In chemistry, this analysis
focuses on the soap's molecular structure. Soap molecules are typically
long chains with a polar (hydrophilic) head and a nonpolar (hydrophobic)
tail.

Tensile strength depends on the soap's intermolecular forces. The

hydrophilic heads can form hydrogen bonds with water molecules, while
the hydrophobic tails tend to aggregate together. When soap is stretched,
these forces come into play.

Soap's tensile strength is generally low because the relatively weak van der
Waals forces and hydrogen bonds between molecules can be easily
disrupted under tension. This characteristic makes soap effective at
dispersing and emulsifying substances but less suitable for applications
requiring high tensile strength.

Chemical composition:-
The chemical composition of soap typically consists of molecules known as
fatty acids and alkali. Here's a simplified explanation:

1. *Fatty Acids*: These are usually derived from natural fats or oils, such as
palm oil, coconut oil, or olive oil. Fatty acids are composed of long
hydrocarbon chains with a carboxylic acid group (-COOH) at one end.
Common fatty acids used in soap making include lauric acid, myristic acid,
palmitic acid, and stearic acid.

2. *Alkali*: The alkali used in soapmaking is usually either sodium

hydroxide (NaOH) for solid soap bars or potassium hydroxide (KOH) for
liquid soap. When an alkali is mixed with fatty acids in a process called
saponification, it produces soap molecules and glycerin as a byproduct.

3. *Glycerin*: Glycerin is a natural humectant that forms during the

saponification process. It helps to retain moisture on the skin and is often a
desirable component in soap.

4. *Water*: Water is used in the soapmaking process to facilitate the

chemical reaction between the fatty acids and alkali. It also helps in
dissolving and diluting the soap mixture.

5. *Fragrances, Colorants, and Additives*: Depending on the type of soap

and its intended use, additional ingredients like fragrances, colorants, and
various additives may be included for scent, color, or specific properties
(e.g., exfoliants or moisturizers).

Varieties of soaps:-
Certainly! Soap can come in various varieties, and their chemistry can vary

based on the ingredients used. Here are explanations of a few common

soap varieties and their chemistry:

1. Bar Soap:-

Bar soaps are typically made using a combination of fatty acids, such as

stearic acid and palmitic acid, and sodium hydroxide (NaOH). This

chemical reaction is known as saponification. The reaction converts

these ingredients into soap molecules (sodium salts of fatty acids) and

glycerin.

2. Liquid Soap:-

Liquid soaps are created through saponification as well, but they use a

different alkali called potassium hydroxide (KOH) instead of sodium

hydroxide. This results in a softer soap suitable for liquid form. The

chemistry is similar to bar soap, with the formation of soap molecules

and glycerin.

3. Transparent Soap:-
Transparent soaps are made by adding solvents like alcohol or glycerin

to the soap mixture. This alters the soap's molecular structure, making it

more transparent. The chemistry still involves saponification but with

additional steps to achieve transparency.

4. Glycerin Soap:-

Glycerin soap is known for its moisturizing properties. It contains a high

proportion of glycerin, a byproduct of saponification. Glycerin is a

humectant, which means it attracts and retains moisture on the skin.

Glycerin soap chemistry is similar to regular soap but with a focus on

preserving glycerin content.

5. Antibacterial Soap:-

Antibacterial soaps often contain additional active ingredients, such as

triclosan or triclocarban, designed to kill or inhibit the growth of bacteria.

The primary soap chemistry remains the same, with the addition of

antibacterial agents for enhanced germ-fighting properties.

6. Medicated Soap:-
Medicated soaps may include ingredients like sulfur, salicylic acid, or

benzoyl peroxide to treat specific skin conditions such as acne or fungal

infections. The chemistry involves combining these medicinal agents with

standard soap ingredients.

7. Herbal or Natural Soap:-

Herbal or natural soaps often use botanical extracts, essential oils, or

herbs for fragrance and potential skin benefits. The base soap chemistry

is the same as for regular soap, but additional natural ingredients are

incorporated.

8. Specialty Soaps:-

Specialty soaps like goat milk soap use unique ingredients like goat's

milk, which contains natural fats and lactic acid. These ingredients are

combined with traditional soap chemistry to create distinct properties.