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Chemistry: It’s All About “Stuff”. Chapter 1. Chapter Outline. 1.1 “Stuff” Is Matter 1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter 1.3 Classifying Matter: Mixture or Pure Substance 1.4 Elements, Compounds, and the Periodic Table 1.5 How Matter Changes.
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Chemistry:It’s All About “Stuff” Chapter 1
Chapter Outline 1.1 “Stuff” Is Matter 1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter 1.3 Classifying Matter: Mixture or Pure Substance 1.4 Elements, Compounds, and the Periodic Table 1.5 How Matter Changes Chapter 1
1.1 “Stuff” Is Matter • “Stuff,”or matter, is anything that takes up space, for example, a book, a bottle, air in a balloon, or a chair. Matter: Volume • Anything that takes up space has volume. • Volumeis a measure of the amount of space occupied by a substance. • Some commonly used units of volume are milliliter (mL), cubic centimeter (cc; same volume as a mL), and liter (L). Chapter 1
Graduated cylinders, pipettes or burettes, are used to measure volume. • The appropriate device for the accuracy required should be used. Chapter 1
1.1 “Stuff” Is Matter, Continued Matter: Mass • Anything that takes up space has mass and can be weighed. • Mass is the amount of matter in a substance and remains the same regardless of location. • The common unit of mass is the gram (g). • Mass and weight are related. Chapter 1
1.1 “Stuff” Is Matter, Continued • Scales, or balances, are used to measure mass. • For example, the mass and weight of a 1-kilogram (1000-g) object would be the same. Chapter 1
1.1 “Stuff” Is Matter, Continued • Densityis mass/volume. • Typical units for solids are g/cm3 • Typical units for liquids are g/mL • Typical units for gases are kg/cm3 Chapter 1
1.1 “Stuff” Is Matter, Continued Metric Units, Prefixes, and Conversion Factors • The metric system is a series of standard units for each type of measurable quantity. • Standard metric units: • Mass: gram (g) • Volume: liter (L) • Length: meter (m) Chapter 1
1.1 “Stuff” Is Matter, Continued • Prefixes are used to represent fractions or multiples of a metric unit of measurement. • Using the information in the above table, equivalency relationships can be determined. Such equivalencies can be used as conversion factors to convert one unit to another. Chapter 1
1.1 “Stuff” Is Matter, Continued To convert 100 mg to grams we find that the equivalency relationship for Table 1.1 shows that 1 mg = 0.001 g or 1000 mg = 1 g. Chapter 1
1.1 “Stuff” Is Matter, Continued States of Matter • Common states of matter are solid, liquid, or gas. • A solid has a definite shape and volume. Particles in a solid are tightly packed. • A liquid has a definite volume, but its shape changes depending on the container it is in. Particles in a liquid are less orderly and move about freely. • A gas has no definite volume or shape. Particles in a gas are disordered and rapidly moving. Chapter 1
1.1 “Stuff” Is Matter, Continued Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter • Gases are used to study the behavior of matter. • Gases are affected by changes in their environment such as increases or decreases in temperature and pressure. • Temperature and pressure are factors that change the motion of the particles in a gas and have an affect on the volume of a gas. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Gases and Pressure • Pressure is defined as a force exerted against a given area. • Pressure measurements are expressed in units of pounds per square inch (psi) and millimeters of mercury (mmHg). • Pounds per square inch (psi) isa measurement of the force applied to an area of 1 square inch. The atmospheric pressure at sea level is 14.7 psi. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Millimeters of Mercury (mm Hg) is a measurement of the pressure derived by the force exerted by the Earth’s surrounding atmosphere. atm psi torr (like mm Hg) Referenced to sea level. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Pressure and Volume—Boyle’s Law • In the mid 1600s, Robert Boyle discovered that the volume of a gas decreases as the pressure on that gas increases. Temperature and amount of gas were not allowed to change. • Boyle’s law states that the volume of a gas at constant temperature is inversely proportional to the pressure. Boyle’s law is expressed as: V α 1/P Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Mathematically, Boyle’s law looks like this: PiVi = PfVf where Pi = the initial or starting pressure Vi = the initial or starting volume Pf = the final or ending pressure Vf = the final or ending pressure Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Effect of Pressure on the Volume of Gas • Assume you have a sealed cylinder with 500 mL of gas at a pressure of 1 atm. • If you increase the pressure to 2 atm, the volume of the gas will decrease to a volume of 250 mL (one-half the initial volume). • If you increase the pressure to 3 atm, the volume of the gas will decrease to a volume of 167 mL ( one-third the initial volume). Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Breathing is a practical application of Boyle’s law. http://wwwhttp://www.youtube.com/watch?v=NB1aCBId6qA.youtube.com/watch?v=NB1aCBId6qA Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Math Matters: Significant Figures • All measurements have uncertainty. • Significant figures are the digits known with certainty plus the estimated digit. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Rules for counting significant figures are summarized in Table 1.2 below. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Calculator Numbers and Rounding • In multiplication and division:The answer is rounded to have the same number of significant digits as the number of significant digits in the least significant starting number. • In addition and subtraction: The answer is rounded to give the same number of decimal places as the number with the fewest decimal places. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Rules for Rounding a Number • If the first digit to be dropped is 4 or less, remove it and the remaining digits. • If the first digit to be dropped is 5 or greater, increase the last retained digit by 1 and remove all the other digits. • In both cases, zeros are substituted as placeholders where appropriate. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued • Note that the Celsius and Kelvin scales are offset by 273 degrees. Mathematically, this relationship is expressed as: Kelvin (K) = Celsius (°C) + 273 • The relationship between oF and oC is: Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Temperature and Volume—Charles’s Law Charles’s lawstates that the volume of a fixed amount of gas at constant pressure is directly proportional to its temperature. In other words, the volume of a gas will increase as the temperature increases, and a volume of gas will decrease as temperature decreases. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Charles’s law can be applied as shown: where T = temperature, V = volume, and the subscripts i and f stand for initial and final, respectively. Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Chapter 1
1.2 A Closer Look at Gases—An Introduction to the Behavior of Matter, Continued Chapter 1
1.3 Classifying Matter: Mixture or Pure Substance Mixtures • Mixtures are a combination of two or more substances and can be further classified as: • Homogeneous mixture: One whose composition is the same throughout. Air is an example. • Heterogeneous mixture: One whose composition is not uniform. An example would be spaghetti sauce. Chapter 1
1.3 Classifying Matter: Mixture or Pure Substance Pure Substances A pure substance is matter that is made up of only one substance and can be of two types: • An element • One type of atom • One symbol - H, Ne, U, He • A compound is made up of two or more elements that are chemically joined together • Two or more symbols – H2O, Fe2O3 , MgSe Chapter 1
1.4 Elements, Compounds, and the Periodic Table Periodic Table • Shows all the elements found on Earth. • Consists of small blocks with a letter or two in its center and numbers above and below these letters. Chapter 1
1.4 Elements, Compounds, and the Periodic Table Periodic Table, Continued • Letters represent the elemental symbol/name. • The first letter of the symbol is always capitalized, and if a second letter is present, it is lowercase. For example, H = hydrogen, Li = lithium. • Know the first 36 element names/symbols plus Ba, Ag, Au, Hg, Sn, Pb and I Chapter 1
1.4 Elements, Compounds, and the Periodic Table Periodic Table, Continued Some elements have symbols that do not match the first letters of their name. For example, sodium = Na, gold = Au. Their symbols are derived from the Latin names of the element. Chapter 1
1.4 Elements, Compounds, and the Periodic Table Periodic Table, Continued A group is a vertical column of blocks. Each group has a number and letter designation. • Groups 1A–8A are main group elements. – Group 1A are the alkali metals. – Group 2A are the alkaline earth metals. – Group 7A are the halogens. – Group 8A are the noble gases. • Groups with B designations are transition elements. Alkali metals and water Chapter 1
1.4 Elements, Compounds, and the Periodic Table Periodic Table, Continued Aperiodis a horizontal row of blocks. The periods are numbered 1 to 7 with sections of periods 6 and 7 set apart at the bottom of the periodic table. – Lanthanides are Period 6 elements with atomic numbers of 58–71, which are set apart at the bottom of the periodic table. – Actinides are Period 7 elements with atomic numbers of 90–103, which are set apart at the bottom of the periodic table. Chapter 1
1.4 Discovery and abundance of the Elements 113 known elements
1.4 Abundance of the Elements UNIVERSE by atom
1.4 Abundance of the Elements CRUST OCEAN ATMOSPHERE by mass ATMOSPHERE78% N2 and 21% O2
1.4 Abundance of the Elements on EARTH BODY by mass BODY by atom
1.4 Elements Memorize the names and symbols of the 1st 36 elements and the following 8 common elements: Ag silver Sn tin I iodine Ba barium Pt platium Au gold Hg mercury Pb lead
1.4 Elements Memorize the names and symbols of the 1st 36 elements
1.4 Elements, Compounds, and the Periodic Table Compounds • Compounds contain two or more elements chemically combined. • Chemical formulasidentify both the type and number of atoms of each of the elements in a compound. • Examples of chemical formulas are H2O, CO2, NaCl for compounds water, carbon dioxide, and table salt, respectively. Chapter 1
1.5 How Matter Changes Physical Change • A physical change results in a change in the form of matter, but its identity remains unchanged. • Water, H2O, can undergo a physical change from solid to liquid to gas. Chapter 1
1.5 How Matter Changes Chapter 1