SYLLABUS INDEX CARD NAME MAJOR (IF YOU DON T HAVE ONE INTEREST) WHAT DO YOU WANT TO BE WHEN YOU GROW UP?

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1 WELCOME CHEMISTRY 131: PRINCIPLES OF CHEMISTRY Mrs. DeVos September 19, 2011 SYLLABUS INDEX CARD NAME MAJOR (IF YOU DON T HAVE ONE INTEREST) WHAT DO YOU WANT TO BE WHEN YOU GROW UP? WHY ARE YOU TAKING THIS CLASS? WHAT IS YOUR GOAL FOR THIS CLASS? _ ICEBREAKER 1 2 WHAT DO YOU NEED TO SUCCEED? You will need Math Skills Algebra; scientific calculator But not like this Hard Work Positive Attitude NOTES ON PROBLEM SOLVING Read carefully; find information given and what is asked for Find appropriate,, Check for, and Check for a 3 4 CHAPTER 1: THE CENTRAL SCIENCE Chemistry The study of and the Matter Anything that has and takes up SUGGESTED CHAPTER PROBLEMS a, b, & c

2 THE SCIENTIFIC METHOD A set of guidelines followed by scientists Gather data through and Identify in collected data Summarize their findings in a Formulate a In time, a hypothesis may evolve into a CLASSIFICATION OF MATTER Chemists classify matter as either a: A Substance: A form of matter that has and Substances can be either or Substances differ from one another in and may be identified by,,, and other properties. 7 8 STATES OF MATTER All substances can, in principle, exist in three states of matter. The three states of matter can be CHANGE OF STATE Heat Energy 9 TERMS OF CHANGING Solid Liquid: Liquid Gas: / Gas Liquid: Liquid Solid: Solid Gas: Gas Solid: STATES SOLIDS & LIQUIDS Solids : Particles are in an Little freedom of motion Liquids: Particles are, but Particles are past one another of the container 12 2

3 GASES Classification of Matter Gases : Particles Particles have No definite or takes the shape and volume of its container. States of Matter: Can be interconverted solid liquid gas ( ) gas liquid solid ( ) 13 have particles that are held closely together in an ordered fashion. Particles in a are close together but are not held rigidly in position. Particles in a have significant separation from each other and move freely. 14 ELEMENTS An element is: A substance that by chemical means. Examples: Iron (Fe), Mercury (Hg), Oxygen (O), and Hydrogen (H). May consist of or. Atoms of an element Molecular form of an element 15 COMPOUNDS Most elements can combine with other elements to form. A Compound: Is a substance composed of two or more elements.. Separation of a compound into its constituent elements requires a. A compound may consist of or. Molecules of a compound 16 MIXTURES A Mixture Is a of Substances distinct identities universal constant composition A mixture into pure components without changing the identities of the components. SUBSTANCE OR MIXTURE? For example: / /

4 TYPES OF MIXTURES Homogeneous: The throughout. Example: Salt dissolved in water. Heterogeneous The throughout. Example: Sugar mixed with iron fillings CLASSIFICATION OF MATTER CLASSIFY THE FOLLOWING Aluminum Foil Baking Soda Milk Air Copper Wire SCIENTIFIC MEASUREMENT Used to measure of matter Quantitative properties are properties that can be must always include a unit. Units: system: Foot, gallon, pound, etc. system: Meter, liter, kilogram, etc INTERNATIONAL SYSTEM OF UNITS (SI) Revised metric system was designated for universal use by scientists. There are seven SI base units: METRIC PREFIXES King Henry Drinks Much Dark Chocolate Milk Kilo, Hecto, Deca, Meter (Base Unit), Deci, Centi, Milli 24 4

5 DIMENSIONAL ANALYSIS A problem solving method employing conversion factors to change one measure to another often called the factor-label method For example: Let s convert inches to meters 2.54 cm = 1.00 in and 100 cm = 1 meter MASS SI Base Unit ( ) ~ 2.2 pounds Most common:,, The an object contains Mass and weight are not equivalent! Mass is it does not change. Weight depends on and *Note that neither limited the number of significant figures in the result because they both consist of exact numbers TEMPERATURE ( C) Water freezes at 0 C Water boils at 100 C (K) The absolute scale: C = K Lowest possible temperature = 0K (no particle motion!) Celsius and Kelvin are equal in magnitude ( F) The English system (9/5) C + 32 = F C = ( F 32) 1.8 VOLUME Derived unit: (m 3 ) The unit (L) is more commonly used in the laboratory setting. It is equal to a decimeter cubed (dm 3 ) DENSITY Ratio of mass to volume d = (g/ml) m = (g) V = (ml or cm 3 ) * Gas volumes are typically expressed in g/l, solids are often expressed as g/cm 3 WATER to density rule: Temperature increases 4 C to 100 C density follow the rule, it. Temperature increases from 0 C to 4 C density actually. Due to unique qualities of water. Water is amazing! It shouldn t be a Will discuss more in chapter

6 CALCULATING DENSITY We will do this in lab : Shape: Dimensions & Calculate Volume Shape: Measure Dimensions Indirect Measurement Method:» : Measure and of a certain quantity of the substance. CALCULATING DENSITY : and are proportional. So, as pressure, volume. Density of a is determined by measuring the of the quantity of gas and the of the container. psi? = how many pounds of force are exerted by the molecules, per square inch of area. We will not be dealing with properties of gases until chapter 5. CALCULATING DENSITY Calculate density of a sample of Al that has a mass of 16.8 g and a volume of 6.2 cm 3 PRACTICE Given that 25.0 ml of mercury has a mass of g, calculate (a) the density of mercury and (b) the mass of ml of mercury. Solution: a: b: 34 SPECIFIC GRAVITY A comparison of the of a substance with the density of (a standard) Numerically, the! Ex: Density of Cobalt is 8.9 g/ml Specific Gravity is SPECIFIC GRAVITY Hydrometer Used to measure the. We will use this in lab. 36 6

7 ENERGY The capacity to do. Base unit of measurement: Two Types: Forms KINETIC ENERGY (KE) Energy of Equation: m =, v = From the equation we see: objects at the same velocity have a KE. An objects KE with increasing. Mechanical Energy,, POTENTIAL ENERGY (PE) energy of an object due to its. POTENTIAL ENERGY potential energy: Ex:, Chemically Important forms: Stored in: such as carbohydrates, fats and proteins Given off during CONSERVATION OF ENERGY Law of of Energy: Energy can neither be nor. Can be from one form to another. HEAT AND TEMPERATURE Measure of the average molecular motion of the particles. Commonly measured in Celsius, or Kelvin Measure of the of energy in the system Commonly measured in. SI unit. 7

8 CALORIES,,, 1 kcal = 1000 calorie 1 Calorie = 1000 calories 1 Calorie = 1 kcal SPECIFIC HEAT The amount of necessary to the of any substance. Each substance has its specific heat. It is a property similar to or melting point. Equation: Amt. of Heat = (your book) 1 calorie = Joules HEAT TRANSFER CALCULATIONS Amt of Heat = EXAMPLE PROBLEM 1 How many calories are required to heat 371g of water from 25 C to 93 C? Units: J = ( ) x x ΔT = = ( - ) *You should be able to solve for any variable in the equation including T 1 or T 2 EXAMPLE PROBLEM 2 If we add 767 cal of heat to 42g of ethanol at 21 C, what is the final temperature? There are two types of numbers used in chemistry: 1) numbers which have values 1 kg = 1000 g 1 dozen = 12 object any number obtained by 2) numbers numbers obtained by any method 8

9 An inexact number must be reported so as to are the in a reported number. The in a measured number is referred to as the digit. The number of significant figures can be determined using the following guidelines: 1) Any digit significant 2) Zeros nonzero digits significant 3) Zeros to the of the first nonzero digit are significant 1129 m 109 cm kg The number of significant figures can be determined using the following guidelines: 4) Zeros to the of the last nonzero digit are significant m 5) Zeros to the of the last nonzero digit in a number that does point may or may not be significant m In and, the answer have more digits to the right of the decimal point than any of the original numbers two digits after the decimal point three digits after the decimal point round to two digits after the decimal 20.1 one digit after the decimal round to In and, the number of significant figures in the final product or quotient is that has the number of significant figures. 1.4 x = round to (limited by 1.4 to significant figures) 11.57/ = round to (limited by to significant figures) numbers can be considered to have an number of significant figures and the number of significant figures in a result. In calculations with multiple steps, of the calculation to any. 9

10 An empty container with a volume of cm 3 is weighed and found to have a mass of 72.5 g. The container is filled with a liquid and reweighed. The mass of the container and the liquid is g. Determine the density of the liquid to the appropriate number of significant figures. ACCURACY & PRECISION Two ways to gauge the quality of a set of measured numbers. Accuracy: Precision: 56 ACCURATE OR PRECISE? PRACTICE Describe the accuracy and precision for each set of the following data: Three students were asked to find the mass of an aspirin tablet. The true mass of the tablet is 0.370g. Student A Student B Student C g 0.357g 0.369g g 0.375g 0.373g g 0.338g 0.371g Avg: 0.333g 0.357g 0.371g SOLUTION 59 10