Saponification and Soaps Chem Lab Flashcards

Questions and Answers

What happens when a fatty acid is reacted with NaOH?

RC(=O)O-Na+ + H2O

Why is ethanol added to the reaction mixture of fat and base in the making of soap?

To facilitate the mixing of fat/oil and NaOH (aq).

Why is the product of saponification a salt?

Because it results from the reaction of fatty acids with sodium hydroxide.

Describe the appearance of your soap.

The appearance depends on the fat or oil used for the saponification. Signup and view all the answers

How would soaps made from vegetable oils differ from soaps made from animal fat?

Vegetable oils produce liquid soaps because of unsaturated fatty acids, while animal fats produce solid soaps due to saturated fatty acids. Signup and view all the answers

How does soap remove an oil spot?

The non-polar tails of soap embed themselves in the oil spot, forming a micelle soluble in water. Signup and view all the answers

What are the pH levels of water, lab soap, commercial soap, and detergent?

Water: 7.0 Signup and view all the answers

Does water, lab soap, commercial soap, and detergent foam?

Water: None Signup and view all the answers

How do water, lab soap, commercial soap, and detergent interact with oil?

Commercial soap: Soluble Signup and view all the answers

How did water, lab soap, commercial soap, and detergent react with CaCl2, MgCl2, and FeCl3?

Lab soap formed a precipitate, commercial soap became cloudy, and detergent showed no change. Signup and view all the answers

Which of the solutions were basic, and why?

Laboratory soap and commercial soap are basic because the carboxylate ions react with water to produce hydroxide ions. Signup and view all the answers

What is the equation for the saponification of trimyristin with KOH?

CH2OCOCH2(CH2)11CH3 + 3KOH -> 3H2O + Glycerol + 3K+ + -OCOCH2(CH2)11CH3 Signup and view all the answers

What is saponification?

The hydrolysis of a fat or oil by a base such as NaOH. Signup and view all the answers

What is soap?

The salts of the fatty acids. Signup and view all the answers

What's the product of hydrolysis?

Glycerol and fatty acid salts. Signup and view all the answers

What are soft soaps made with?

KOH instead of NaOH to give potassium salts. Signup and view all the answers

What's the non-polar carbon chain called?

Hydrophobic. Signup and view all the answers

What's hydrophobic attracted to?

Non-polar substances such as grease. Signup and view all the answers

What's hydrophilic?

The polar head of the carboxylate salt. Signup and view all the answers

What happens to soap when it is added to a greasy substance?

The hydrophobic tails embed in the non-polar fats and oils. Signup and view all the answers

Polar heads are attracted to what?

The polar water molecules. Signup and view all the answers

What are clusters of soap particles called?

Micelles. Signup and view all the answers

What do micelles form?

Non-polar oil droplets in the center surrounded by polar heads. Signup and view all the answers

What do all greasy substances form?

Micelles, which can be washed away with water. Signup and view all the answers

The carboxylate ends of soap react with what?

Ca2+, Fe3+, or Mg2+ ions. Signup and view all the answers

What are synthetic cleaning agents?

"Syndets" or detergents, which are not derived from naturally occurring fats or oils. Signup and view all the answers

Why do detergents work well with hard water and in soft water?

They do not form insoluble salts with ions. Signup and view all the answers

What is a typical detergent?

Sodium lauryl sulfate, a biodegradable detergent. Signup and view all the answers

What do the LDF's do?

They interact with the heads of oil and the heads will repel each other. Signup and view all the answers

Study Notes

Saponification Process

Saponification occurs when fatty acids react with NaOH, producing sodium salt of the fatty acid and water.
Ethanol is added to the reaction mixture to assist in emulsifying fat/oil and NaOH.

Properties of Soaps

The appearance of soap is influenced by the type of fat or oil used during saponification.
Soaps from vegetable oils tend to be liquid due to unsaturated fatty acids, while soaps from animal fats are solid because of saturated fatty acids.
Saponification results in the creation of fatty acid salts, which are essentially the soap.

Mechanism of Soap Action

Soap removes oil spots through the formation of micelles, with non-polar tails of soap embedding into oil to render it soluble in water.
Micelles consist of non-polar oil droplets at the center, surrounded by polar heads that interact with water.

Cleansing Efficacy

Lab soap produces some foam, while commercial soaps and detergents generate more foam.
Detergents, unlike traditional soaps, remain effective in hard water because they do not form insoluble salts with metal ions.

Chemical Reactions and Properties

Laboratory and commercial soaps are basic because they contain carboxylate ions that react with water to release hydroxide ions.
Soft soaps are made using KOH, resulting in potassium salts instead of sodium salts used in traditional soaps.

Micelles and Interaction

Soap particles cluster to form micelles, allowing for the entrapment and removal of greasy substances with water.
The hydrophilic polar heads of soap are attracted to water, while hydrophobic tails are drawn to non-polar substances like grease.

Synthetic Detergents

Synthetic agents known as "syndets" are detergents not derived from natural fats/oils and are formulated to function effectively in all water types.
Typical examples include sodium lauryl sulfate, a biodegradable detergent.

Summary of Key Points

Soap acts as an effective cleaning agent due to its unique chemical structure, forming micelles that cut through grease.
Understanding the chemistry of soaps and detergents is crucial for their application in various environments.

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Description

This quiz focuses on the chemistry of saponification and the process of making soap. Each flashcard presents important concepts related to the reaction of fatty acids with alkali and the role of ethanol in soap production. Test your knowledge on the chemical reactions and products involved in this essential chemistry lab.