CHM1045 Exam 1 Study Guide Chapter 1 1 Distinguish between these Qualitative Data obtained in a research study consisting of general observations about the system Quantitative comprising numbers obtained by various measurements of the system Homogenous Composition of the substance is the same throughout ex sugar dissolves in water Heterogeneous composition is not uniform ex sand mixed with iron fillings they remain separate Element substance that cannot be separated into simpler substances by chemical means Compound substance composed of atoms of two or more elements chemically unite in fixed proportions Physical property can be measured and observed without changing the composition or identity Chemical property to observe this property we must carry out a chemical change ex Hydrogen atoms but to form H20 Intensive does not depend on how much matter is being considered ex density is considered an intensive property so is temperature Extensive depends how much matter is being considered ex mass or volume 2 SI Base Units Base Quantity Name of Unit Symbol Length Meter m Mass Kilogram kg Time Second S Electrical current Ampere A Temperature Kelvin K Amount of a Substance Mole mol Luminous Intensity Candela cd 3 Prefixes used with SI Units Mega 10 6 Kilo 10 3 Deci 10 1 Centi 10 2 Milli 10 3 Micro 10 6 4 Temperature Scales Formulas 1 K C 273 15 2 F 9 5C 32 Chapter 2 1 2 3 Know the difference between experiments J J Thomson cathode ray tube experiment Shooting an electron to find its negative Millikan s oil drop experiment The could measure the mass of an electron Rutherford s gold foil experiment atoms aren t organized most of the atoms are empty spaced protons are in the nucleus and opposite charge then electron atomic radius 100pm Chadwick s experiment neutrons mass of protons he had neutrons also equal H 1 He 2 Know the difference between atomic mass and isotope Atomic Z of protons in nucleus Mass A of protons plus neutrons Isotopes atoms of the same element X with different number of neutrons in nuclei Ex 1 20 11 Na 11 protons 11 electrons 9 neutrons Ex 2 Carbon 14 4 6 C 6 electrons 6 protons 8 neutrons Molecule 2 or more atoms in an arrangement diatomic contains 2 atoms ex H2 or O2 Ions Ions atom or group of atoms that has a net charge of positive or negative Cations loss of more than one electron from a neutral atom ion with a positive charge Example Na Atom Na Ion 11 protons 11 protons 11 electrons 10 electrons Anions net charges is negative Increase in negative electrons Cl atom Cl ion 17 Proton 17 proton 17 electrons 18 electrons Monoatomic ions Contain only one atom Ex Mg2 Fe3 S2 N3 Na ClPolyatomic ions ions that have a net charge of negative or positive Ex NH 4 OH CN4 Naming oxoacids and formula given name of oxoacid Contain hydrogen oxygen and another element usually written with H first Naming 1 Addiction of one O atoms to the ic acid The acid is called per ic acid Thus adding an O atom to HCl03 changes chloric acid to perchloric acid HClO4 2 Removal of one O atom from the ic acid The acid is called ous acid Thus nitric acid NHO3 becomes nitrous acid HNO2 3 Removal of 2 O atoms Acid id called hypo ous acid When HBrO3 is converted to HBrO hypobromous acid Reference Oxoacids H2CO3 Carbonic Acid HClO3 Chloric Acid HNO3 Nitric acid H3PO4 Phosphoric acid H2SO4 Sulfuric acid Naming Oxoanions 1 When H s are removed the ic you use ate instead Ex CO3 derived from H2CO3 is called carbonate 2 H removed from ous acid will end with ite Ex anion CLO 2 derived from HClO3 is called chlorite 3 If not all hydrogen s removed must indicate it Ex H2PO4 dehydrogen phosphate 4 Hydrates Compounds that has a specific number of water molecules attached to them Ex BaCl2 2H2O Barium Chloride dehydrate CHAPTER 3 Average Atomic Mass Carbon 12 Carbon 13 98 9 1 10 12 98 9 13 110 12 01 amu Know what a mole is and how to determine its mass Is the amount of a substance that contain as many elementary entities as there are atoms in exactly 12g of the carbon 12 isotope Avogadro s 6 022 1023 1g 6 022 1023 1 amu 1 661 10 24 Molecular Mass Sum of the atomic mass in amu in the molecule Ex H2O 2 atomic mass H atomic mass of O 2 1 008 16 00 18 02 amu Density Formula D Mass Volume Scientific Notation 1 Express 568 72 in scientific notation 5 68 10 2 2 Express 00000772 7 72 10 6 Addition Subtraction 1 7 4 103 2 1 103 9 5 103 2 4 31 104 3 9 103 4 31 39 4 70 104 3 2 22 10 2 4 10 10 3 2 22 410 1 81 10 2 Multiplication Division add exponent for multiplication and subtract for division 1 8 0 104 5 0 102 4 0 107 2 6 9 107 6 9 107 5 1 7 10 5 3 0 10 5 3 Significant Figures Always express your final answer to the correct number of sig figs Exact numbers have an infinite of sig figs and can be ignored when determining how many sig fig you need in your final answer For multi dividing take the lowest sig fig all around Sub add take the least to the right of the decimal for sig fig Rule 1 Any digit that s not zero is sig fig Rule 2 Zeroes between nonzero digits are significant ex 701 03 5 Rule 3 Zeroes to the left of the first nonzero is not significant ex 000701 3 Rule 4 numbers more than one then are all zeroes to the right of the decimal are significant ex 2 0 3 Rule 5 If 1 the only the zeroes at the end of the number between are significant Ex 090 2 3005 4 00420 3 Rule 6 Ni umbers with no decimal points trailing zeroes may may not be sig fig Ex 400 4 102 1 4 0 102 2 4 00 102 3 Dimensional Analysis procedure to convert between units Given unit Desired Unit desired unit Given Unit Accuracy How close a measurement is to the true value Precision How close a set of measurement are to each other Difference between ionic and molecular Ionic made of cations and anions with the exception ammonium ion NH 4 all cations are derived from metal atoms Binary Compounds compounds formed from just 2 elements o First element named is the metal cation followed by a nonmetallic anion o Anion is named by taking fist part of element and adding ide Tertiary Compounds compounds consisting of 3 elements o Transition metals form more than one type of cation o Use assigns to the endings ous to the cation with fewer positive charges and ic to the one with the most positive o EX Fe2 ferrous Fe3 Ferric o Metallic elements use Roman Numerals Mn2 M2O Manganese ll …
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