CHEM 1211 Lecture 2 Outline of Last Lecture I Quick Reminders a Homework b Weekly Diagnostics c WebAssign d Clickers II Chemistry Basics A Matter and Energy B Natural Laws III Atoms A Model B Make up C Examples IV Compounds V Molecules A Alloy B Examples Makeup C Periodic Table VI States of Matter Macroscopic A Kinetic Molecular Theory a Solids b Liquids c Gases Outline of Current Lecture I Changing States A How do we change states 1 Adding energy 2 Removing energy II Mixtures A Homogeneous B Heterogeneous III Chemical and Physical Properties A Chemical B Physical C Extensive properties D Intensive properties IV Metric Prefixes V Unites of Measurement A Mass B Weight C Common Conversion Factors a Length b Volume VI How to use Numbers A Significant Figures B Exact Numbers VII Rules A Rule 1 B Rule 2A C Rule 2B D Rule 2C E Rule 3 F Rule 4 G Rule 5 VIII Use of Numbers A Example 1 B Multiplication Division Rule C Perimeter Current Lecture I Changing States A How do we change states 3 Adding energy heating 4 Removing energy cooling II Mixtures Composed of two or more substances A Homogeneous ag Solutions mix easily will always be solutions B Heterogeneous III Chemical and Physical Properties A Chemical 1 Rusting oxidation 2 Chemical reactions B Physical 1 Changes in state 2 Density color solubility C Extensive properties depend on quantity D Intensive properties do not depend on quantity IV Metric Prefixes Name Symbol Multiplier mega M 106 kilo k 103 deka da 10 100 base units Deci d 10 1 centi c 10 2 milli m 10 3 micro 10 6 nano n 10 9 pico p 10 12 A Example 200cJ 200 x 10 2J V Unites of Measurement A Mass measure of quantity of matter in a body B Weight measure of gravitational attraction for a body C Common Conversion Factors came from British system a Length 1 1m 39 37 inches 2 2 54 cm 1 inch EXACT b Volume 1 1 Liter 1 06qt 2 1qt 0 946 Liters see appendix C or inside back cover of your book for more Most will be given if needed on tests VI How to use Numbers A Significant Figures digits believe to be correct by the person making the measurement depends on the sensitivity of instrument used B Exact Numbers have infinite number of significant figures 1 dozen exact number VII Rules A Rule 1 c 123 mm 3 sig figs d 23 44 ug 5 sig figs e 7845 kg 4 sig figs All non zero digits are significant B Rule 2A a 0 000357 3 sig figs b 0 02332 4 sig figs c 0 13 2 sig figs Leading zeros are never significant C Rule 2B a 1300 ambiguous or 2 sig figs b 1300 4 sig figs c 2000 am or 1 sig fig d 0 023400 5 sig figs e 0 023400 5 sig figs Trailing zeros are significant ONLY if decimal point is present D Rule 2C a 1300 033 7 sig figs b 1303 4 sig figs c 2001 4 sig figs d 3 0604 5 sig figs Imbedded zeros are ALWAYS significant E Rule 3 a 15 eggs infinite b 100 pencils infinite c 348 students infinite Look at units Exact numbers have infinite numbers of sig figs F Rule 4 use scientific notation to remove doubt a 2 40 x 103 mantissa 3 sig figs b 5 003 x 106 4 sig figs G Rule 5 scientific notation for logarithms a X Log 2 40 x 103 x 3 380 3 sig figs VIII Use of Numbers D Example 1 12 13 14 13 3 5 4 sig figs 5 estimated E Multiplication Division Rule A lxwxh 13 35 x 8 3 110 805 round off to 110 1 1 x 102 F Perimeter 13 3 5 13 3 5 8 3 8 3 0 DO NOT WRITE Least significant figure Answer 43 2