Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 1: Problem 22

A match is lit and held under a cold piece of metal. The following observations are made: (a) The match burns. (b) The metal gets warmer. (c) Water condenses on the metal. (d) Soot (carbon) isdeposited on the metal. Which of these occurrences are due to physical changes, and which are due to chemical changes?

Short Answer

Expert verified
Observations (a) and (d) are due to chemical changes, as burning and formation of soot involve the formation of new substances. Observations (b) and (c) are due to physical changes, as the metal getting warmer and water condensing are changes in state, appearance, or location without altering the chemical composition.

Step by step solution

01

Observation (a): The match burns

Burning is a process in which a substance reacts with oxygen to give out heat and light. This is known as combustion, which is a chemical change. During the burning of the match, the chemicals in the match react with oxygen to produce new substances like carbon dioxide, water, and heat. So, observation (a) is due to a chemical change.
02

Observation (b): The metal gets warmer

When the match burns, it releases heat. This heat is transferred to the cold piece of metal, causing it to become warmer. The metal's increase in temperature is a result of heat transfer and not a change in its chemical composition. Therefore, observation (b) is due to a physical change.
03

Observation (c): Water condenses on the metal

The combustion of the match produces water vapor as one of its products. As the hot water vapor comes into contact with the cold metal surface, it cools down and condenses back into liquid water. Condensation is a change in the state of matter, from gas to liquid, and does not involve any changes in the chemical composition. Hence, observation (c) is due to a physical change.
04

Observation (d): Soot (carbon) is deposited on the metal

During the burning or combustion process of the match, carbon is produced as one of the by-products. The carbon in the form of soot then deposits on the metal surface. As carbon is a new substance produced as a result of a chemical reaction, observation (d) is due to a chemical change. In conclusion, observations (a) and (d) are due to chemical changes, while observations (b) and (c) are due to physical changes.

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

Gold can be hammered into extremely thin sheets called gold leaf. An architect wants to cover a 100 \(\mathrm{ft} \times 82\) ft ceiling with gold leaf that is five-millionths of an inch thick. The density of gold is \(19.32 \mathrm{g} / \mathrm{cm}^{3},\) and gold costs \(\$ 1654\) per troy ounce \((1\) troy ounce \(=31.1034768 \mathrm{g}) .\) How much will it cost the architect to buy the necessary gold?

Identify each of the following as measurements of length, area, volume, mass, density, time, or temperature: (a) 25 \(\mathrm{ps}\) (b) \(374.2 \mathrm{mg},\) (c) 77 \(\mathrm{K}\) , (d) \(100,000 \mathrm{km}^{2},\) (e) 1.06\(\mu \mathrm{m}\) ,(f) \(16 \mathrm{nm}^{2},(\mathrm{g})-78^{\circ} \mathrm{C},(\mathbf{h}) 2.56 \mathrm{g} / \mathrm{cm}^{3},(\mathrm{i}) 28 \mathrm{cm}^{3} \cdot[\) Section 1.5\(]\)

Carry out the following operations and express the answer with the appropriate number of significant figures. $$ \begin{array}{l}{\text { (a) } 320.5-(6104.5 / 2.3)} \\ {\text { (b) }\left[\left(285.3 \times 10^{5}\right)-\left(1.200 \times 10^{3}\right)\right] \times 2.8954} \\ {\text { (c) }(0.0045 \times 20,000.0)+(2813 \times 12)} \\ {\text { (a) } 863 \times[1255-(3.45 \times 108)]}\end{array} $$

Musical instruments like trumpets and trombones are made from an alloy called brass. Brass is composed of copper and zinc atoms and appears homogeneous under an optical mi-croscope. The approximate composition of most brass objects is a \(2 : 1\) ratio of copper to zinc atoms, but the exact ratio varies somewhat from one piece of brass to another.(a) Would you classify brass as an element, a compound, a homogeneous mixture, or a heterogeneous mixture? (b) Would it be correct to say that brass is a solution? [ Section 1.2\(]\)

Label each of the following as either a physical process or a chemical process: (a) rusting of a metal can, (b) boiling a cup of water, (c) pulverizing an aspirin, (d) digesting a candy bar, (e) exploding of nitroglyerin.
See all solutions

Recommended explanations on Chemistry Textbooks

Kinetics

Read Explanation

Making Measurements

Read Explanation

Chemical Reactions

Read Explanation

Chemistry Branches

Read Explanation

Chemical Analysis

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