/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 50 What is a micelle? How do the mi... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 20: Problem 50

What is a micelle? How do the micelles formed by soap molecules suspend greasy dirt in a solution?

Short Answer

Expert verified
A micelle is an aggregate of surfactant molecules, like soap, dispersed in a liquid colloid such as water. It has a hydrophilic (water-loving) exterior and a hydrophobic (water-repelling) interior. Soap molecules form micelles in water, with the hydrophobic tails pointing inward, capturing greasy dirt particles. The polar heads of the soap molecules interact with the water, keeping the micelle-dirt complex suspended in the solution, and preventing the micelles from clumping together due to their negative charge. This allows the micelles with enclosed dirt particles to be easily washed away.

Step by step solution

01

Define a micelle

A micelle is an aggregate of surfactant molecules dispersed in a liquid colloid, such as water. Surfactants are molecules that have both hydrophilic (water-loving) and hydrophobic (water-repelling) parts. In a micelle, the hydrophilic parts face the surrounding water, while the hydrophobic parts are clustered together in the center, creating a protective sphere around them. This arrangement minimizes the contact between the hydrophobic parts of the surfactant molecules and the water.
02

Explain soap structure

Soap is a type of surfactant that consists of a long hydrophobic tail (usually made of hydrocarbon chains) and a polar, hydrophilic head. When soap is added to water, the hydrophobic tails of the soap molecules repel the water and gather toward each other, creating a spherical structure called a micelle. The hydrophilic heads remain on the outer surface of the sphere, interacting with the surrounding water.
03

Explain how micelles remove grease

Greasy dirt is not soluble in water, meaning it does not dissolve or mix easily with water. When soap is added to water containing grease, the soap molecules form micelles with the hydrophobic tails pointing inward. The hydrophobic tails in the center of the micelle can effectively 'capture' the greasy dirt particles, because they prefer interactions with the nonpolar grease molecules over the polar water molecules.
04

Describe the suspension of greasy dirt

Once the greasy dirt particles are captured by the micelles, the polar heads of the soap molecules that are in contact with water keep the micelle-dirt complex suspended in the solution. This is because the polar heads of the soap form a barrier around the micelle, and interact with the water molecules, forming a stable colloid. The hydrophilic head also has a negative charge, which prevents the micelles from clumping together due to electrostatic repulsion between the negatively charged heads. As a result, the micelles with the enclosed dirt particles stay dispersed in the water, allowing them to be easily washed away.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Sketch the general formula for an \(\alpha\) -amino acid. In the systematic naming system we use for organic compounds, what number will always be used for an \(\alpha\) -amino acid to specify the location of the amino group?

The starting material in the body for the synthesis of other steroids is _________.

Although both starch and cellulose are polymers of glucose, starch is digestible by humans and cellulose is not. How do the structures of these polysaccharides differ, resulting in their different digestibility?

How is the secondary structure of a protein related to its function in the body? Give examples.

The process of _________ involves treating a fat with sodium hydroxide so that the fatty acids present are converted to their sodium salts.
See all solutions

Recommended explanations on Chemistry Textbooks

Chemical Reactions

Read Explanation

Kinetics

Read Explanation

Inorganic Chemistry

Read Explanation

Making Measurements

Read Explanation

Physical Chemistry

Read Explanation

The Earths Atmosphere

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.