Saponification: Making Soap

Summary

This video script details a soap-making process using a saponification reaction. It begins with 2ml of castor oil and 5ml of ethanol in a 100ml beaker, followed by the careful addition of 10ml of sodium hydroxide solution. The mixture is heated and stirred to hydrolyze the triglycerides, forming free fatty acids that react with the alkali to create soap. To precipitate the soap, a saturated sodium chloride solution is added, followed by cooling in iced water. The soap is then filtered using a standard funnel and paper, resulting in a final product that lathers in water. The video concludes with a reminder of the historical roots of soap-making and a caution about the presence of hazardous alkali in the homemade soap.

Takeaways

• 🧪 The process described is the creation of soap using a saponification reaction.
• 🌟 The primary ingredients are castor oil as the fat or ester, and sodium hydroxide as the alkaline solution.
• 🍶 Ethanol is added to help the castor oil dissolve in the aqueous alkaline solution.
• 🔍 A concentrated sodium hydroxide solution, specifically 5 moles per decimeter cubed, is used for the reaction.
• 🧼 The reaction involves the hydrolysis of triglyceride molecules found in the castor oil, facilitated by the alkaline solution.
• 🔥 The mixture of oil, ethanol, and sodium hydroxide is heated and stirred to speed up the saponification process.
• 🧂 Sodium chloride is added to precipitate the soap from the mixture, forming a suspension that can be filtered.
• ❄️ Cooling the mixture in iced water aids in the precipitation of the soap, increasing the yield.
• 🕒 The mixture is left to cool for approximately 15 minutes with occasional stirring.
• 📚 The term 'saponification' is derived from 'SAPO', the Latin word for soap, and relates to the historical process of soap making.
• 🚫 The final soap product still contains hazardous alkali and is not safe for washing until further processing.

Q & A

What is the main purpose of using ethanol in the soap-making process described in the script?

Ethanol is used to help the castor oil dissolve better because oil and water don't mix well, and the alkaline solution added later is essentially water.

Why is sodium hydroxide used in the soap-making process?

Sodium hydroxide is used because it reacts with the long-chain fatty acids found in fats and oils to form soap, which are the sodium salts of these fatty acids.

What is the molarity of the sodium hydroxide solution used in the script?

The sodium hydroxide solution used has a molarity of five moles per decimeter cubed (5 M).

What is the role of stirring the mixture of oil and alkali in the soap-making process?

Stirring the mixture helps to speed up the hydrolysis reaction, breaking down the triglyceride molecules in the castor oil to make free fatty acids that combine with the alkali to form soap.

Why is the beaker containing the mixture placed in hot water and stirred?

Placing the beaker in hot water and stirring helps to speed up the saponification reaction, facilitating the hydrolysis of fat molecules and the formation of soap.

What is the purpose of adding sodium chloride to the soap mixture?

Sodium chloride is added to precipitate out the soap from the suspension, as it helps in the separation of soap from the mixture.

How does cooling the mixture in iced water affect the soap-making process?

Cooling the mixture in iced water helps the soap to precipitate out more effectively, potentially increasing the yield of soap.

What historical context is provided about the origins of soap-making in the script?

The script mentions that early soaps were likely made as early as 5000 years ago by the ancient Babylonians who boiled animal fats with ashes containing potassium hydroxide.

What is the final step in the soap-making process described in the script?

The final step is filtering off the precipitated soap using a filter funnel and filter paper, allowing the filtrate to drip through and leaving behind the soap.

How is the soap's quality tested in the script?

The soap's quality is tested by taking a small amount of distilled water, adding a spatula full of the soap, and shaking it to see if it forms a lather.

Why is it cautioned against using the homemade soap for washing in the script?

It is cautioned because the homemade soap still contains hazardous alkali, which can be harmful if used for washing without proper neutralization and purification.

Outlines

00:00

🧼 Soap Making Process Introduction

The video script begins with an introduction to the process of soap making through a saponification reaction, which involves fats or esters reacting with an alkaline solution. The primary fat used is castor oil, which is mixed with ethanol to improve solubility. The alkaline solution is a concentrated sodium hydroxide solution, chosen for its ability to react with long-chain fatty acids to form soap. The script explains the hydrolysis reaction that breaks down triglyceride molecules in the fat, leading to the formation of free fatty acids that combine with the alkali to create an impure soap.

🔬 Preparing the Soap Mixture

The script details the careful measurement of sodium hydroxide solution and its combination with castor oil and ethanol in a beaker. The mixture is then heated in hot water and stirred to accelerate the hydrolysis of fat molecules. The addition of sodium chloride, or common salt, is described as a method to precipitate the soap from the suspension, followed by cooling the mixture in iced water to enhance soap yield. The historical context of soap making is briefly mentioned, dating back to ancient Babylonian practices.

📝 Filtering and Testing the Soap

The final steps of the soap-making process are outlined, including the filtration of the precipitated soap using a filter funnel and filter paper. The script emphasizes the importance of testing the soap by mixing it with distilled water to check for lather formation, which indicates successful soap production. However, a cautionary note is sounded regarding the presence of hazardous alkali in the soap, which makes it unsuitable for washing until further purification. The video concludes with a recap of the saponification process and an invitation for viewers to like and subscribe for more content.

Keywords

💡Saponification

Saponification is the chemical process of making soap from fats or oils and an alkali, typically sodium hydroxide. This reaction is crucial to the video's theme, as it demonstrates the basic chemistry behind soap making. In the video, the saponification reaction involves castor oil and sodium hydroxide, leading to the creation of soap.

💡Castor Oil

Castor oil is a type of fat used in the video as the primary ingredient for making soap. It acts as the 'ester' in the saponification process. The video shows how castor oil, when mixed with sodium hydroxide and ethanol, undergoes a reaction to produce soap, illustrating the role of fats in soap production.

💡Sodium Hydroxide

Sodium hydroxide, also known as lye, is a strong alkali used in the saponification process to react with fats and oils to create soap. In the video, it is highlighted as a key reactant, particularly emphasizing its concentration (5 moles per decimeter cubed) and its role in breaking down fat molecules to form soap.

💡Hydrolysis

Hydrolysis is a chemical reaction that involves breaking down molecules with water. In the context of the video, hydrolysis refers to the breakdown of triglyceride molecules in fats, specifically castor oil, during the soap-making process. This reaction is crucial for converting fats into free fatty acids, which then form soap.

💡Ethanol

Ethanol is an alcohol used in the video to help dissolve castor oil, which is otherwise difficult to mix with water. The video explains that ethanol aids in the dissolution of oil, facilitating a smoother saponification reaction when the sodium hydroxide solution, which is mostly water, is added.

💡Triglyceride

Triglycerides are the main constituents of natural fats and oils, consisting of three fatty acids and one glycerol molecule. In the video, the hydrolysis of triglycerides in castor oil is a key step in the saponification process, where these molecules are broken down to form free fatty acids, essential for soap formation.

💡Alkaline Hydrolysis

Alkaline hydrolysis refers to the chemical reaction where an ester (in this case, fats like castor oil) is broken down by an alkali (such as sodium hydroxide) in the presence of water. This process, demonstrated in the video, is central to the creation of soap, as it facilitates the conversion of fats into soap.

💡Precipitation

Precipitation in the context of this video refers to the process of separating the soap from the liquid mixture after the saponification reaction. The video illustrates this by adding sodium chloride (salt) to the soap suspension, causing the soap to solidify and separate from the solution, allowing it to be filtered out.

💡Sodium Chloride

Sodium chloride, commonly known as table salt, is used in the video to precipitate the soap out of the liquid mixture. By adding a saturated solution of sodium chloride, the soap becomes less soluble, allowing it to solidify and be separated from the mixture. This step is critical for obtaining the final soap product.

💡Filter Paper

Filter paper is a porous paper used to separate solids from liquids. In the video, it is used in a filtration setup to remove the solid soap from the remaining liquid after precipitation. The use of filter paper is essential for obtaining a clean, final product by removing any impurities or excess liquid.

Highlights

Introduction to the process of making soap using a saponification reaction.

Use of castor oil as the fat or ester in the soap-making process.

Addition of ethanol to help dissolve castor oil due to its solubility issues with water.

Careful measurement of sodium hydroxide solution, a highly concentrated alkaline used in the reaction.

Explanation of the hydrolysis reaction in soap-making involving fatty acids and sodium hydroxide.

Technique of heating and stirring the mixture to speed up the saponification reaction.

Introduction of sodium chloride to precipitate the soap from the mixture.

Cooling the mixture in iced water to facilitate soap precipitation.

Historical context of soap-making dating back to ancient Babylonian times.

Setting up a filter funnel and filter paper for soap filtration.

Demonstration of the soap's effectiveness through its ability to form a lather in water.

Caution regarding the hazardous nature of the soap before it is fully processed.

Final product presentation and testing of the soap's lathering ability.

Recap of the saponification process and its significance in soap-making.

Invitation for viewers to like and subscribe for more informative content.

Emphasis on the importance of the hydrolysis reaction in the soap-making process.

Mnemonic device provided to remember the word 'saponification' and its Latin origin.

Ethanol's role in aiding the mixing of oil and alkaline solution in soap-making.

The significance of the concentration of sodium hydroxide solution in the reaction.

Transcripts

hello today I'm going to be making a

soap and I'm going to be using a

saponification reaction that is the

reaction between fats or an ester and an

alkaline so we're going to start with 2

milliliters of castor oil that's going

to be our fat or our ester and I'm going

to transfer that into a 100 milliliter

beaker to that I'm going to add 5 mils

of ethanol to help the castor oil to

dissolve better because you know oil and

water don't mix and the alkaline

solution I'm going to be adding later on

is essentially water so this ethanol is

going to help the castor oil to dissolve

now I'm going to very carefully measure

out 10 milliliters of sodium hydroxide

solution this is highly concentrated

it's five moles per decimeter cubed five

molar solution we're using sodium

hydroxide because soaps of the sodium

salts formed when long-chain fatty acids

found in fats and oils react with sodium

hydroxide according to this word

equation this is what's known as a

hydrolysis reaction

which means breaking down the

triglyceride molecules the ester

molecules in the fat using water because

the alkaline solution is mostly water

we're now going to speed up the reaction

by standing the beaker containing the

ethanol sodium hydroxide and castor oil

in water hot water and stirring I was

stirring the mixture of oil and alkali

the fat molecules in the castor oil are

being hydrolyzed which means broken down

to make free fatty acids these free

fatty acids are then going to combine

with the alkali to make an impure soap

which we can filter off later this

process is called the alkaline

hydrolysis of esters so once we've

stirred the mixture inside the beaker of

hot water for five minutes we're going

to precipitate out the soap because at

the moment it's just a suspension inside

the mixture to do this we're going to

need sodium chloride or common salt I've

got a saturated solution of sodium

chloride here and I'm going to measure

out 10

and centimeters cute and milliliters of

it and then I'm going to add it to our

soap suspension in the 100 milliliter

beaker and again I'm going to stir after

this we're going to need to cool the

mixture in iced water this is going to

help the soap to precipitate out the

longer we can possibly leave it the

greater the yield of soap is going to be

I'm going to leave my mixture on ice for

about 15 minutes stirring occasionally

every couple of minutes or so one way of

helping yourself to remember that

saponification is all about manufacture

of soap is to remember that the word

SAPO is the Latin word for soap you can

also remind yourself about the

ingredients used in the soap manufacture

process by thinking about the history of

early soaps we think they were made as

early as 5000 years ago when the ancient

Babylonians boiled animal fats with

ashes which contain potassium hydroxide

so that's fats with an alkali the last

thing we need to do is filter off the

soap that we've precipitated out using

the sodium chloride so I've just set up

a standard filter funnel filter paper

arrangement I'm going to scrape the

mixture into it and wait until the

filtrate has finished dripping through

and here's the final product to test it

all we need to do is take a very small

amount of distilled water and put a

spatula full of our soap in it and shake

it to see if it forms a lather and it

does so we've successfully made soap but

it's important to note that I'm not

going to wash with this still has very

hazardous alkali in it to recap

saponification means making soap from a

fat or oil and sodium hydroxide via a

hydrolysis reaction

please hit like and subscribe if it

helps see you next time

you