CHEM 101 1nd Edition Lecture 2 Outline of Last Lecture I. General Class InformationII. Roots of ChemistryIII. Chemistry and the Scientific MethodIV. States of MatterV. Classification of Matter – Elements and DefinitionsVI. FormulasOutline of Current Lecture I. Classifying Matter - CompoundsII. Physical Properties of MatterIII. Chemical PropertiesIV. Units of MeasurementV. Units of EnergyVI. Precision and AccuracyCurrent LectureII. Classifying Matter - Compoundsa. Figure out whether you have a pure substance or a mixture.i. Figure 1.7 in Bookb. If it is a mixture:i. Homogenous – Uniformed Compositionii. Heterogeneous – Ununiformed CompositionIII. Physical Properties of Mattera. Can be measured or observed without changing the composition or identity of the substance.i. Such as: color, state of matter, melting point, boiling point, density, solubility, conductivity, malleability, ductility, and viscosityb. Densityi. Is equal to Mass (g) / Volume (cm3)ii. Most substances get more dense as they go from gas to liquid.1. An important exception to this is Water.c. Physical changes occur with no change in the composition of the substance, whichis why they can be used for identification.d. Intensive and Extensive PropertiesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Intensive1. Does not depend of quantity of mattera. Density of a flake of gold, and a gold ring are the same.2. Often useful for identifying a materialii. Extensive1. Depends on quantity of mattera. Mass and volume of a flake of gold, are different that the mass and volume of a gold ring.IV. Chemical Propertiesa. Describe the ways a substance may change, or react to create new substances.i. Such as: flammability, corrosively, and reactivity.b. Chemical reactions should be balanced due to the Law of Conservation of Matter.c. These reactions involve changes in energy.V. Units of Measurementa. There is a metric unit for every quantity that can be measured.i. Mass = Kilogram (kg)ii. Length = Meter (m)iii. Time = Second (sec)iv. Temperature = Kelvin (K)v. Amount of Substance = Mole (mol)vi. Electric Current = Ampere (A)1. A formula sheet will be given for tests, focus on using not memorizing.b. Common Prefixesi. Found in Table 1.3 of the Bookii. Will want to memorize1. Focus on abbreviation and what it is numerically.c. Temperaturei. Working with Celsius and Kelvin1. K = 273.15 + Degrees in Celsius2. 1 Kelvin = 1 Celsiusd. Additional Measurementsi. Volume1. 1 cubic centimeter (cm3) = 1cm x 1cm x 1cm = 1 mLii. Mass1. Measure of quantity of matter contained, grams (g).iii. Weight1. A measure of gravitational attraction for the body2. Force = Mass x Gravitational Acceleration iv. Mass is fixed, weight is relative.1. You weigh less on the moon than on earth, but still have the same mass.VI. Units of Energya. The primary measurement is the Joule, named after James Jouleb. 1 calories is the heat required to raise the temperature of 1g of water by 1 degree Celsiusi. 1 kcal = 1 food calorie = 1000 caloriesc. Food and Caloriesi. Use fixed scaleii. An average caloric measurement was determined using calorimetry (the food is burned and the energy transferred into heat is measured)1. 1 g protein = 4 kcal2. 1 g carbohydrate = 4 kcal3. 1 g fat = 9 kcal4. 1 g alcohol = 7 kcald. Dimensional Analysisi. Using conversions to simplify the units the problem is measured in.ii. 1 serving of Cheerios has 110 food calories. How many degrees will this amount of energy heat 1 gallon of water?1. 110000 cal x 1 g H2O 1.0 o C x 1 gallon x 1 liter = ? 1 gallon 1 cal 3.78 liter 1000 giii. When set up correctly, dimensional analysis eliminates all extra units. VII. Precision and Accuracya. Accuracyi. Refers to how closely a measured value agrees with the correct value.ii. Measured with error1. Error in Measure = Experimental Value – Accepted Valueiii. Percent Error1. Percent Error = (Error in Measure / Accepted Value) x 100b. Precisioni. Refers to how closely individual measurements agree with one anotherc. Examplei. When darts are thrown at a dart board:1. If they spread out all over the board, they are low in Precision and Accuracy2. When they are clumped together, but far away from the center, they are high in precision and low in accuracy.3. When they hit the center and are clumped together, they are high in precision and accuracy.d. Standard Deviationi. The standard deviation of a group of measurements is equal to the square root of: the sum of the squares of the deviation for each measurement from the average, divided by one less that the number of measurements1.a. X = each measurementb. xK = the mean or averagec. n = the number of valuesd. Σ = means we sum across the