Chapter 1 Table of Contents Return to TOC Chapter 1. Introduction to Chemistry

Chapter 1 Table of Contents Return to TOC Copyright © Cengage Learning. All rights reserved 1.1 Chemistry: An Introduction 1.2 What is Chemistry? 1.3 Solving Problems Using a Scientific Approach 1.4 The Scientific Method 1.5 Learning Chemistry

Section 1.1 Chemistry: An Introduction Return to TOC Copyright © Cengage Learning. All rights reserved Why Is Chemistry Important?

Section 1.1 Chemistry: An Introduction Return to TOC Copyright © Cengage Learning. All rights reserved Ice cubes in water (H 2 O)Graphite and Diamond (C)

Section 1.1 Chemistry: An Introduction Return to TOC Copyright © Cengage Learning. All rights reserved New materials New pharmaceuticals New energy sources Food supplies Help the environment

Section 1.1 Chemistry: An Introduction Return to TOC Copyright © Cengage Learning. All rights reserved CHLOROFLUOROCARBONS (CFCs) Solve the problems… Double-edged sword Freon-12---noncorrosive nature and ability to resist decomposition Freon-12---destroy ozone (O3)in the upper atmosphere.

Section 1.1 Chemistry: An Introduction Return to TOC Copyright © Cengage Learning. All rights reserved In this course, you will: Learn the principles of chemistry. Become a better problem solver!

Section 1.1 Chemistry: An Introduction Return to TOC QUESTION Which of the following statements is false? 1.A knowledge of chemistry is useful to almost everyone. 2.The principles of chemistry are inherently neither good nor bad – it’s what we do with this knowledge that really matters. 3.A major by-product of studying chemistry is that you will become a better problem solver. 4.Chemical industries are the ones responsible for all our environmental problems today.

Section 1.1 Chemistry: An Introduction Return to TOC ANSWER Choice #4 is false. Although chemical industries have contributed to some environmental problems, they are not responsible for all of them. The industries that apply the chemical sciences are now determined to be part of the solution to our environmental ills rather than part of the problem. : Chemistry: An Introduction

Section 1.2 What Is Chemistry? Return to TOC Copyright © Cengage Learning. All rights reserved The science that deals with the materials of the universe and the changes these materials undergo. (Chemical changes) The central science.  Understanding most other fields of science requires an understanding of chemistry. 1.Wood burns in air, forming water, carbon dioxide and other substances. 2. Eggs, flour, sugar and baker powder are mixed and baked to yield a cake. 3. The definition of the term chemistry is learned and stored in the brain.

Section 1.3 Solving Problems Using a Scientific Approach Return to TOC Copyright © Cengage Learning. All rights reserved 1.Recognize the problem and state it clearly. a)Making an observation.

Section 1.3 Solving Problems Using a Scientific Approach Return to TOC Copyright © Cengage Learning. All rights reserved 2.Propose possible solutions to the problem or possible explanations for the observation. a)Formulating a hypothesis.

Section 1.3 Solving Problems Using a Scientific Approach Return to TOC Copyright © Cengage Learning. All rights reserved 3.Decide which of the solutions is the best or decide whether the explanation proposed is reasonable. a)Performing an experiment. Scientific thinking can help you in all parts of your life!

Section 1.4 The Scientific Method Return to TOC Copyright © Cengage Learning. All rights reserved Steps in the Scientific Method Process that lies at the center of scientific inquiry. The difference between observations and theories. An observation is something is witnessed and can be recorded. A theory is an interpretation-a possible explanation of why nature behaves in a particular way. The difference between a Law and a theory. A law tells what happens A theory (model) is our attempt to explain why it happens.

Section 1.4 The Scientific Method Return to TOC QUESTION Which of the following statements is false? 1.A law is a summary of observed behavior. For example, studies of innumerable chemical changes have shown that the total mass of the materials involved is the same before and after the change. 2.A theory is an explanation of behavior – why nature behaves in a particular way. 3.If a theory is disproven, then all of the observations that support that theory must also be disproven. 4.A law tells what happens.

Section 1.4 The Scientific Method Return to TOC ANSWER Choice #3 is false. A theory can be wrong in its attempt to explain why a behavior occurs but that does not mean that the observed behavior in itself is also wrong. : The Scientific Method

Section 1.4 The Scientific Method Return to TOC Copyright © Cengage Learning. All rights reserved Scientific Models Summarizes what happens. Law Theory (Model) An attempt to explain why it happens. Set of tested hypotheses that gives an overall explanation of some natural phenomenon. Hypothesis A possible explanation for an observation.

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Learn the vocabulary. Memorize important information. Learn and practice processes. Keep working and learning from your mistakes. Ask questions!

Section 1.5 Learning Chemistry Return to TOC Prerequisite Science Skills

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved 2.1 Scientific Notation 2.2 Units 2.3 Measurements of Length, Volume, and Mass 2.4 Uncertainty in Measurement 2.5 Significant Figures 2.6Problem Solving and Dimensional Analysis 2.7Temperature Conversions: An Approach to Problem Solving 2.8Density

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Measurement Quantitative observation. Has 2 parts – number and unit.  Number tells comparison.  Unit tells scale.

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Technique used to express very large or very small numbers. Expresses a number as a product of a number between 1 and 10 and the appropriate power of 10.

Section 1.5 Learning Chemistry Return to TOC This depends on the number of places the decimal point is moved and in which direction.

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Using Scientific Notation If the decimal point is moved to the left, the power of 10 is positive. 345 = 3.45 × 10 2 If the decimal point is moved to the right, the power of 10 is negative = 6.71 × 10 –2

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Concept Check Which of the following correctly expresses 7,882 in scientific notation? a)7.882 × 10 4 b)788.2 × 10 3 c)7.882 × 10 3 d)7.882 × 10 –3

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Concept Check Which of the following correctly expresses in scientific notation? a)4.96 × 10 –5 b)4.96 × 10 5 c)4.96 × 10 –7 d)496 ×

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Math Review

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Quantitative observation consisting of two parts.  number  unit : tell scale or standard is being used to represent the results of the measurement. Nature of Measurement Measurement Examples  20 grams  70 miles/hour

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved The Fundamental SI Units Physical QuantityName of UnitAbbreviation Masskilogramkg Lengthmeterm Timeseconds TemperaturekelvinK Electric currentampereA Amount of substancemolemol SI Units: the need for common units standards

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Prefixes are used to change the size of the unit. Prefixes Used in the SI System

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Fundamental SI unit of length is the meter. Length (SI unit: meter)

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Conversion between inch and cm: 1 inch = 2.54 cm

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Volume (SI unit: cubic meter, m 3 ) Measure of the amount of 3-D space occupied by a substance. Commonly measure solid volume in cm 3. 1 mL = 1 cm 3 1 L = 1 dm 3

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Graduated Cylinders mL “zero was at the bottom of the scale, with values increasing going up the cylinder. “ Buret, mL Pipet, mL a buret has zero at the top with values increasing going down the scale. 0

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Mass (SI unit: kilogram, kg) Measure of the amount of matter present in an object. 1 kg = lbs 1 lb = g

Section 1.5 Learning Chemistry Return to TOC Copyright © Cengage Learning. All rights reserved Triple beam balance Electronic balance Analytical balance