1 Final Exam Outline Chapter 1: - Pure or not pure? Elements: 1 type of atom only, Ca, F2 Compounds: 2 or more different atoms in a FIXED ratio, NaCl, N2O4 Mixtures: No fixed ratio Homogeneous - uniform Heterogeneous – not uniform - Sig figs Move left to right & start counting when you reach a number between 1 – 9. Zeros at the end of a number only count IF a DECIMAL point is present Addition & Subtraction Rule = Column Multiplication & Division Rule =Fewest Round only when your next mathematical step is a different function than the one you just performed - Converting Prefix definitions (Mega, milli, micro…) Squaring and cubing conversion factors - Density = mass/volume It is a conversion factor, and never start calculations with conversion factors2 Chapter 2: - Nuclear Symbols: Mass # (A) = protons + neutrons Atomic # (Z) = protons (& electrons in a NEUTRAL atom) - Isotopes: same protons, different neutrons Use the abundance of each isotope for an element to calculate the atomic weight on the periodic table - Periodic Table design: Families/Groups: Columns (alkali metals, Halogens…) Periods: Rows Types of elements: Metals: Left of black line Non-metals: Right of black line Metalloids: Touching black line XAZ3 - Naming: General Rule: what comes first stays the same, what comes second is altered Diatomic gases: 7 exist Molecular Compounds: nonmetals only Use the general Rule (always end in –ide) & use di, tri, tetra prefixes Ionic Compounds: metal & nonmetal (possibly polyatomic ions) HAS IONS! Cations: name stays same, only use a roman numeral (RN) if capable of multiple charges (RN = charge) Anions: altered - Monatomic = -ide - Polyatomic = -ate or –ite Use CHARGES when forming (cris-cross when needed) Acid Compounds: start with H Binary Acids: general formula of hydro_____ic acid Polyatomic Acids: depends on anion - -ate ending turns into –ic acid - -ite ending turns into –ous acid Use CHARGES when forming (cris-cross when needed)4 Chapter 3: - Writing balanced equations Form chemicals (IONICS & ACIDS use CHARGES) Balance with coefficients (no fractions, reduce if possible) - Types of reactions: NOTE: use charges when forming products! Combination: 2 natural state elements 1 compound Decomposition: 1 compound 2 natural state elements Combustion: C&H’s +O2(g) CO2(g) + H2O(g) Single Replacement: A + BC AC + B (CHAPTER 4) Use Activity Series to predict if rxn will occur Free element (A) must be ABOVE the cation (B) in other reactant Double Replacement: AB + CD AD + CB (CHAPTER 4) Reaction occurs if PRODUCE one of the following - Solid (aka. Precipitate, ppt) - Liquid (H2O, neutralization rxn, acid + base water + salt) - Gas (H2CO3 or H2SO3 decompose into water & CO2 or SO2) - Weak electrolyte PHASES: Don’t need to memorize entire solubility table, but should be familiar with the ions that are ALWAYS soluble NH4+1 NO3-1 C2H3O2-1 Column 1 cations (Na+1, Li+1, K+1 …) - Mass of elements & compounds Atomic weight = mass of 1 atom of an element Formula mass(or weight) = mass of 1 molecule Molar mass or Molecular weight = mass of 1 mole of an element or molecule (unit = g/mol) Percent composition = 100compound of mass Totalcompoundin element of massx Unit=amu H2O: 2(1.0)+16.0=18.0amu Or 18.0 g/mol5 - Conversion factors Ratio: chemical formula Avogadro’s number: 6.022x1023 Molar Mass: from periodic table Mol:Mol Ratio: Coefficients in balanced equation Molarity = moles/L (Chapter 4) Mol:Heat = need Hrxn (Chapter 5) NOTE: If given info about 2 different chemicals, write a balanced equation!! - Limiting Reactants If given info about BOTH reactants, must find out which one is limiting Convert BOTH reactants to the SAME product, compare, least amount came from limiting reactant EXCESS = Initial Used Amount Calculate Used Amount by start with limiting reactant & convert to excess reactant - Percent yield = 100ltheoreticaactualx - Empirical vs. Molecular Formulas Molar masses differ by some factor (x) Formula(x) Emperical of MassFormulaMolecular of Mass Actual usually given Theoretical must be calculated (start w/reactant & convert to product)6 Chapter 4: - Molarity = moles/L - Dilution: 2211VMVM (used for 1 chemical only!) - Titration: Given info about both reactants, but interested in solving for info about a reactant NOTE: If given info about 2 different chemicals, write a balanced equation!! - Electrolytes Strong: 100% ions present Ionic compounds, Strong Acids & Strong Bases Weak: Partial ions present (more molecule than ion) Weak acids & weak bases Non: NO ions present Molecular compounds - Total/Net ionic equations: describe how compounds actually exist in a beaker Only break up a compound if AQUEOUS & STRONG ELECTROLYTE Chapter 5: - Thermodynamics: study of energy (E), unit = Joules; Potential & Kinetic energy Types of energy (E): Heat (q): Endothermic: q is positive; Exothermic: q is negative Work (w): Done BY system is negative; Done ON system is positive - Enthalpy of reaction Hrxn = Products – Reactants Exothermic, heat lost (product) H is negative Endothermic, heat absorbed (reactant) H is positive MOL: Heat conversion factor!! - Calorimetry: - Hess’s Law: If reverse rxn, change sign of H, If multiply (or divide) the rxn, multiply (or divide) the H - Standard Heat of Formation Hf : form 1 mole of product, from its elements in their natural state - Food Energy 2211smkgJwqE TmCqqqsgssurroundinsystem7 Chapter 10: - Characteristics of gases Fill container Compressible Homogeneous - Pressure Units: (atm, mmHg, torr, Pa) - STP: 0C & 1atm - Laws: Boyle: P&V Charles’s: V&T Avogadro’s: V&n IDEAL GAS LAW, make sure you have the correct units! Combined gas law: Same gas at 2 different conditions - Mm & Density with ideal gas law - Partial Pressures - Kinetic Molecular Theory (KMT): Pressure due to
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