Robert Gardner
Chemistry! BEST SCIENCE PROJECTS
Using Acids, Bases, Metals, Salts, and Inorganic Stuff Robert Gardner
Copyright © 2004 by Robert Gardner All rights reserved. No part of this book may be reproduced by any means without the written permission of the publisher. Library of Congress Cataloging-in-Publication Data Gardner, Robert, 1929– Chemistry science fair projects using acids, bases, metals, salts, and inorganic stuff / Robert Gardner. v. cm. — (Chemistry! best science projects) Includes bibliographical references and index. Contents: Identifying substances — Conservation of matter — Some chemical reactions and their reaction speeds — Energy in chemical and physical changes — Acids, bases, ions, and an electric cell. ISBN 0-7660-2210-2 (hard cover) 1. Chemistry—Experiments—Juvenile literature. 2. Science projects— Juvenile literature. [1. Chemistry—Experiments. 2. Experiments. 3. Science projects.] I. Title. II. Series. QD38.G35 2004 540’.78—dc22 2003027476 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 To Our Readers: We have done our best to make sure all Internet Addresses in this book were active and appropriate when we went to press. However, the author and the publisher have no control over and assume no liability for the material available on those Internet sites or on other Web sites they may link to. Any comments or suggestions can be sent by e-mail to
[email protected] or to the address on the back cover.
Illustration Credits: Tom LaBaff Cover Photo: Copyright © 2002–2004 Art Today, Inc. (model); Matt Meadows/Photo Researchers, Inc. (beaker).
Introduction . . . . . . . . . . . . . . . . . . . . . . . . .
5
Identifying Substances . . . . . . . . . . . . . . . .
11 14 18 21 26 29 31
1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
Separating the Components of a Mixture. . Separating by Chromatography. . . . . . . . Using Density to Identify Liquids . . . . . . Using Density to Identify Solids . . . . . . . The Density of Pennies, New and Old . . Identification by Melting. . . . . . . . . . . . . The Melting and Freezing Temperature of Water (Ice). . . . . . . . . . . . . . . . . . . . . 33 The Boiling Temperature of Water . . . . . 39 Using Solubility to Identify Substances . . 43
Conservation of Matter . . . . . . . . . . . . . . . 2.1 2.2 2.3
Does Weight Change When Water Freezes? . . . . . . . . . . . . . . . . . . . . 47 Lavoisier and a Chemical Law . . . . . . . . 48 Paper Clips, Washers, “Chemical Formulas,” and Laws of Nature . . . . . . . 54
Some Chemical Reactions and Their Reaction Speeds . . . . . . . . . . . . . . . . 3.1 3.2 3.3
46
59 Rusting of Iron. . . . . . . . . . . . . . . . . . . . 60 What Fraction of Air Is Oxygen? . . . . . . 61 Preparing and Testing Oxygen . . . . . . . . 64
3.4 3.5
The Rate at Which Hydrogen Peroxide Decomposes . . . . . . . . . . . . . . . 68 Factors Affecting the Rate of a Reaction . . 73
Energy in Chemical and Physical Changes . . . . . . . . . . . . . . . . . . . . 4.1 4.2 4.3 4.4 4.5
77 The Energy (Heat) Needed to Melt Ice . . 79 The Energy (Heat) Needed to Boil Water . . . . . . . . . . . . . . . . . . . . . . . 82 The Heat of Condensation . . . . . . . . . . . 88 Energy Changes During Physical and Chemical Changes . . . . . . . . . . . . . . . . . 93 A Chemical Reaction: Reactants, Products, and Energy Changes . . . . . . . . 96
Acids, Bases, Ions, and an Electric Cell 5.1 5.2 5.3 5.4 5.5 5.6
. . 103 Ions and Electric Current . . . . . . . . . . . . 104 Identifying Acids and Bases . . . . . . . . . . 109 Indicator Papers and Sticks. . . . . . . . . . . 114 Neutralization . . .