Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 10: Problem 1

It is possible to balance a paper clip on the surface of water in a beaker. If you add a bit of soap to the water, however, the paper clip sinks. Explain how the paper clip can float and why it sinks when soap is added.

Short Answer

Expert verified
A paper clip can float on water due to surface tension, which is the cohesive force between water molecules that creates a "skin" on the surface of the liquid, supporting the paper clip's weight. However, when soap is added to the water, it acts as a surfactant and lowers the surface tension by disrupting the cohesive forces between water molecules. With the reduced surface tension, the water's surface is unable to support the weight of the paper clip, causing it to sink.

Step by step solution

01

Define surface tension and explain how it helps a paper clip to float

Surface tension is a property of liquids that arises due to the cohesive forces between their molecules. At the surface of a liquid, these forces act to minimize the liquid's surface area, creating a thin "skin" that resists deformation. In the case of a paper clip floating on water, surface tension acts like an invisible film, supporting the weight of the paper clip and preventing it from sinking. This effect is also aided by the paper clip's shape, which distributes its weight over a larger area.
02

Discuss how soap affects surface tension

Soap is a surfactant, a substance that lowers the surface tension of a liquid by disrupting the cohesive forces between its molecules. When added to water, soap molecules have a hydrophobic (water-repelling) end and a hydrophilic (water-attracting) end. The hydrophobic ends of the soap molecules push apart the water molecules at the surface, while the hydrophilic ends bond with the water molecules, reducing the overall surface tension of the water.
03

Explain how the reduced surface tension causes the paper clip to sink when soap is added

When soap is added to the water, the surface tension of the water is reduced due to the presence of soap molecules. With the weaker surface tension, the water molecules are unable to create a strong enough "skin" to support the weight of the paper clip. As a result, the paper clip is no longer able to float on the water's surface and sinks.

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

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

A certain form of lead has a cubic closest packed structure with an edge length of \(492 \mathrm{pm} .\) Calculate the value of the atomic radius and the density of lead.

A topaz crystal has an interplanar spacing \((d)\) of \(1.36 \AA^{\circ}(1 \AA=\) \(\left.1 \times 10^{-10} \mathrm{~m}\right) .\) Calculate the wavelength of the \(\mathrm{X}\) ray that should be used if \(\theta=15.0^{\circ}\) (assume \(n=1\) ).

Some ionic compounds contain a mixture of different charged cations. For example, wüstite is an oxide that contains both \(\mathrm{Fe}^{2+}\) and \(\mathrm{Fe}^{3+}\) cations and has a formula of \(\mathrm{Fe}_{0.950} \mathrm{O}_{1.00} .\) Calculate the fraction of iron ions present as \(\mathrm{Fe}^{3+}\). What fraction of the sites normally occupied by \(\mathrm{Fe}^{2+}\) must be vacant in this solid?

Explain how the evaporation of water acts as a coolant for the earth.

A \(20.0-\mathrm{g}\) sample of ice at \(-10.0^{\circ} \mathrm{C}\) is mixed with \(100.0 \mathrm{~g}\) water at \(80.0^{\circ} \mathrm{C}\). Calculate the final temperature of the mixture assuming no heat loss to the surroundings. The heat capacities of \(\mathrm{H}_{2} \mathrm{O}(s)\) and \(\mathrm{H}_{2} \mathrm{O}(l)\) are \(2.03\) and \(4.18 \mathrm{~J} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}\), respectively, and the enthalpy of fusion for ice is \(6.02 \mathrm{~kJ} / \mathrm{mol}\).
See all solutions

Recommended explanations on Chemistry Textbooks

Making Measurements

Read Explanation

Chemical Analysis

Read Explanation

Physical Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Chemical Reactions

Read Explanation

Nuclear Chemistry

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.

Sign-up for free