Fundamentals of General, Organic, and Biological Chemistry 6th Edition Chapter One Matter and Life

Outline 1.1 Chemistry: The Central Science 1.2 States of Matter 1.3 Classification of Matter 1.4 An Example of a Chemical Reaction 1.5 Chemical Elements and Symbols 1.6 Elements and the Periodic Table Copyright © 2010 Pearson Education, Inc. Chapter One

Goals 1. What is matter? Be able to discuss the properties of matter and describe the three states of matter. 2. How is matter classified? Be able to distinguish between mixtures and pure substances, and between elements and compounds. 3. What kinds of properties does matter have? Be able to distinguish between chemical and physical properties. 4. How are chemical elements represented? Be able to name and give the symbols of common elements. Copyright © 2010 Pearson Education, Inc. Chapter One

Why Study Chemistry? In every aspect of our modern life Long life batteries Materials & miniaturization Cell phones/pagers Laptops Synthetic fibers Dyes CDs/DVDs—silicon wafers Medications DNA sequencing Touches all areas of science Ch 1.1 Chemistry and Its Place among the Sciences

Chemistry and the Sciences Study of matter & its transformations Seeks answers to fundamental questions about: What makes up materials that compose our world How composition affects properties of substances How substances change when they interact with each other = Chemical Reactions

Chemistry and the Sciences Seeks to understand: Underlying structures of matter Forces that determine properties that we observe Apply this knowledge to: Create new materials not found in nature Understand fundamental biological processes

Matter & Its Classifications Anything that has mass & occupies space Mass How much matter given object has Measure of object’s momentum, or resistance to change in motion Weight Force with which object is attracted by gravity Ex. Mass vs. Weight Astronaut on moon & on earth Weight on moon = 1/6 weight on earth Same mass regardless of location

1.1 Chemistry: The Central Science Chemistry is often referred to as “The Central Science” Copyright © 2010 Pearson Education, Inc. Chapter One

Chemistry: The study of the properties and transformations of matter. Matter: Anything that has mass and occupies space – things you can see, touch, taste, or smell. Property: A characteristic that can be used to describe a substance. Substances have both physical and chemical properties. Transformations: A change in the properties of matter with time. There are physical changes and chemical changes. Copyright © 2010 Pearson Education, Inc. Chapter One

Substances have both physical and chemical properties. Physical Properties: Density, color, and melting point are physical properties of matter. Observing a physical property can be done without altering the makeup of a substance. Chemical Properties: Chemical composition, what matter is made of, how matter behaves, are chemical properties. Observing a chemical property alters the substance. Copyright © 2010 Pearson Education, Inc. Chapter One

Physical Change: Does not alter the chemical makeup of a substance. Chemical reactivity is unchanged. Changes in state, changes in particle size, and the formation / separation of mixtures are all examples of physical change. Melting of ice to form liquid water is a physical change. In this case only a change in form takes place. The chemical makeup of the substance remains H2O. Copyright © 2010 Pearson Education, Inc. Chapter One

Chemical Change: Alters the makeup of a substance. Reactivity changes with the formation of new substances. Heat, light, or electrical energy is often emitted or absorbed. Potassium reacting with water is an example of a chemical change. Copyright © 2010 Pearson Education, Inc. Chapter One

Learning Check: For each of the following, determine if it represents a Chemical or Physical Change: Chemical Physical Magnesium burns when heated Magnesium metal tarnishes in air Magnesium metal melts at 922 K Grape Kool-aid lightens when water is added X X X X

1.2 States of Matter Common states of matter are: solid, liquid, and gas. Solid: A substance that has a definite shape and volume. Solids are rigid and dense. Liquid: A substance that has a definite volume but that changes shape to fill the container. Liquids are dense and fluid. Copyright © 2010 Pearson Education, Inc. Chapter One

Common states of matter are: solid, liquid, and gas. Gas: A substance that has neither a definite volume nor a definite shape. Gases are low density fluids. Substances can exist in each of these three states depending on the pressure and the temperature. The conversion of a substance from one state into another is known as change of state. Copyright © 2010 Pearson Education, Inc. Chapter One

The three states - the solid state, the liquid state, and the gaseous state - of water are shown below. Copyright © 2010 Pearson Education, Inc. Chapter One

1.3 Classification of Matter Pure Substance: Matter that is uniform in its chemical composition and properties. Sugar is a pure substance and water is a pure substance. Mixture: A blend of two or more pure substances in any ratio each retaining their identity. Dissolving sugar in water creates a mixture. Physical changes can separate mixtures into one or more pure substances. Evaporation and condensation can separate water from sugar. Copyright © 2010 Pearson Education, Inc. Chapter One

Element: Pure substance that can not be broken down chemically into simpler substances. Hydrogen and oxygen are examples of elements. Chemical Compounds: Two or more elements combined chemically in specific ratios to form a pure substance. Water is a compound composed of two parts hydrogen and one part oxygen. Chemical changes can separate chemical compounds into elements. Water can be broken down into hydrogen and oxygen by passing an electric current through it. Copyright © 2010 Pearson Education, Inc. Chapter One

Classification of Matter

The Classification of Matter by Components Matter can also be classified according to its composition: elements, compounds, and mixtures.

Homogeneous Mixtures Same properties throughout sample Solution Thoroughly stirred homogeneous mixture Ex. Liquid solution Sugar in water Gas solution Air Contains nitrogen, oxygen, carbon dioxide & other gases Solid solution US 5¢ coin – Metal Alloy Contains copper & nickel metals

Heterogeneous Mixtures 2 or more regions of different properties Solution with multiple phases Separate layers Ex. Salad dressing Oil & vinegar Ice & water Same composition 2 different physical states

Learning Check: Classification Hot Cocoa Ice (H2O) White Flour Table Salt (NaCl) Pure substance Element Compound Heterogeneous Mixture Homogeneous Mixture X X X X X X

1.4 Example of a Chemical Reaction Nickel, a solid metal, is mixed with a colorless solution of hydrochloric acid in a test tube. The nickel is slowly eaten away, the colorless solution turns green, and a colorless gas bubbles out of the test tube. Copyright © 2010 Pearson Education, Inc. Chapter One

Between products and reactants, the “” can be read as “to form”. Reactants: One or more starting materials. Between reactants, the “+” can be read as “reacts with”. Products: One or more substances formed as a result of a chemical reaction. Between products, the “+” can be read as “and”. Between products and reactants, the “” can be read as “to form”. Copyright © 2010 Pearson Education, Inc. Chapter One

1.5 Chemical Elements and Symbols 114 elements have been discovered. 90 occur naturally 24 are produced artificially Some familiar elements are iron, tin, carbon, oxygen, hydrogen, sulfur, etc. Some unfamiliar elements are niobium, rhodium, thulium, californium etc. Copyright © 2010 Pearson Education, Inc. Chapter One

Each element has its own unique symbol Each element has its own unique symbol. One or two letter symbols are used to represent elements. The first letter is always capitalized and the second letter is always a lower case. Examples: C, Cr, P, Pb Most symbols are derived from modern names and are easy to remember. Examples: ‘H’ for hydrogen, ‘O’ for oxygen, ‘N’ for nitrogen, etc. Copyright © 2010 Pearson Education, Inc. Chapter One

A few symbols for elements are derived from their Latin names and are more difficult to learn. Examples, ‘Na’ for sodium comes from its Latin name Natrium, ‘Pb’ for lead comes from its Latin name Plumbum. Copyright © 2010 Pearson Education, Inc. Chapter One

Chemical Symbols for Elements One or two letter symbol for each element name First letter capitalized, second letter lower case Ex. C = carbon S = sulfur Ca = calcium Ar = argon Br = bromine H = hydrogen Cl = chlorine O = oxygen Used to represent elements in chemical formulas Ex. Water = H2O Carbon dioxide = CO2 Most based on English name Some based on Latin or German names

Chemical Symbols English Name Chemical Symbol Latin Name Sodium Na Natrium Potassium K Kalium Iron Fe Ferrum Copper Cu Cuprum Silver Ag Argentum Gold Au Aurum Mercury Hg Hydrargyrum Antimony Sb Stibium Tin Sn Stannium Lead Pb Plumbum Tungsten W Wolfram (German)

Chemical Formula: A notation for a chemical compound using symbols and subscripts to show how many atoms of each element are present. When no subscript is given for an element a subscript of ‘1’ is understood. Copyright © 2010 Pearson Education, Inc. Chapter One

1.6 Elements and the Periodic Table Periodic Table: 114 elements in tabular format. Copyright © 2010 Pearson Education, Inc. Chapter One

Metals: Found on the left side of the table. Large amounts of information regarding the properties of elements are embedded in the periodic table. Elements are roughly divided into 3 groups: Metals: Found on the left side of the table. Nonmetals: Found on the right side of the table. Metalloids: Found along a diagonal line between metals and nonmetals. Copyright © 2010 Pearson Education, Inc. Chapter One

A metal (red), a nonmetal (blue), and a metalloid (green) appear in distinct places on the periodic table Copyright © 2010 Pearson Education, Inc. Chapter One

Some common properties of metals are: Metals: 90 of the 114 elements are metals. They appear on the left side of the Periodic Table. Some common properties of metals are: Solid at room temperature (except mercury which is a liquid) Good conductor of heat and electricity Lustrous on fresh surfaces Malleable and ductile Copyright © 2010 Pearson Education, Inc. Chapter One

Metals: (a) Gold is very unreactive and is used primarily in jewelry and in electronic components. (b) Zinc, an essential nutrient, is used in the manufacture of brass, roofing materials, and batteries. (c) Copper is widely used in electrical wiring, in water pipes, and in coins. Copyright © 2010 Pearson Education, Inc. Chapter One

Eleven are gases at room temperature (H, N, O, F, Ne, etc.) Nonmetals: Appear on the right side of the Periodic Table. 17 elements are nonmetals. Eleven are gases at room temperature (H, N, O, F, Ne, etc.) Five are solids (C, P, S, Se, I) One is a liquid (Br). Nonmetals are poor conductors of heat and electricity. Copyright © 2010 Pearson Education, Inc. Chapter One

Nonmetals: (a) Nitrogen constitutes almost 80% of air and is a colorless gas at room temperature. (b) Sulfur, a yellow solid, is found in large underground deposits in Texas and Louisiana. (c) Iodine crystals. Copyright © 2010 Pearson Education, Inc. Chapter One

Metalloids: Seven elements are metalloids Metalloids: Seven elements are metalloids. Their properties are between those of metals and nonmetals. Metalloids are semiconductors and are important to the electronics industry. (a) Boron and (b) silicon are examples of metalloids. Copyright © 2010 Pearson Education, Inc. Chapter One

Chapter Summary Matter is anything with mass that occupies volume. Matter can be classified as solid, liquid, or gas. A solid has a definite volume and shape, a liquid has a definite volume but indefinite shape, and a gas has neither a definite volume nor shape. A substance can be characterized as being either pure or a mixture. A pure substance is uniform in its composition and properties, but a mixture can vary in both composition and properties. Copyright © 2010 Pearson Education, Inc. Chapter One

Chapter Summary Cont. Pure substances are either elements or chemical compounds. Elements are fundamental substances that cannot be chemically changed into anything simpler. A chemical compound can be broken down by chemical change into simpler substances. A property describes or identifies something. A physical property can be seen or measured without changing the chemical identity of the substance. Copyright © 2010 Pearson Education, Inc. Chapter One

Chapter Summary Cont. A chemical property can only be seen or measured when the substance undergoes a chemical change. Elements are represented by symbols. Most symbols are the first one or two letters of the element name. Some symbols are derived from Latin names. All the known elements are organized into a tabular form called the periodic table. Most elements are metals, 17 are nonmetals, and 7 are metalloids. Copyright © 2010 Pearson Education, Inc. Chapter One

WORKED EXAMPLE 1.1 Classifying Matter Classify each of the following as a mixture or a pure substance: (a) Vanilla ice cream (b) Sugar Analysis Refer to the definitions of pure substances and mixtures. Is the substance composed of more than one kind of matter? Solution (a) Vanilla ice cream is composed of more than one substance—cream, sugar, and vanilla flavoring. This is a mixture. (b) Sugar is composed of only one kind of matter—pure sugar. This is a pure substance.

Solution Example 1.2 Physical and Chemical Changes and Properties Determine whether each change is physical or chemical. What kind of property (chemical or physical) is demonstrated in each case? a. the evaporation of rubbing alcohol b. the burning of lamp oil c. the bleaching of hair with hydrogen peroxide d. the forming of frost on a cold night Solution a. When rubbing alcohol evaporates, it changes from liquid to gas, but it remains alcohol—this is a physical change. The volatility (the ability to evaporate easily) of alcohol is a therefore a physical property. b. Lamp oil burns because it reacts with oxygen in air to form carbon dioxide and water—this is a chemical change. The flammability of lamp oil is therefore a chemical property. c. Applying hydrogen peroxide to hair changes pigment molecules in hair that give it color—this is a chemical change. The susceptibility of hair to bleaching is therefore a chemical property. d. Frost forms on a cold night because water vapor in air changes its state to form solid ice—this is a physical change. The temperature at which water freezes is therefore a physical property. .