general Chemistry

UNIT 1: THE FUNDAMENTALS (30% of exam, ~12 questions)

Topics Covered:

• Laws vs. theories

• States of matter (solid, liquid, gas)

• Scientific method

• Physical vs. chemical changes and properties

• Measurement and units

• Significant figures

• Dimensional analysis

• Unit conversions (metric, English, temperature)

• Atomic structure (protons, neutrons, electrons)

• Isotopes and atomic mass

• Reading the periodic table

Skills You Need:

• Classify changes as physical or chemical

• Count significant figures correctly

• Perform calculations with proper sig figs

• Convert between units using dimensional analysis

• Multi-step conversion problems

• Calculate average atomic mass from isotope data

• Determine number of protons, neutrons, electrons

• Identify elements from periodic table information

UNIT 2: BONDING IN CHEMISTRY (30% of exam, ~12 questions)

Topics Covered:

• Electromagnetic spectrum (wavelength, frequency, energy)

• Light and wave properties

• Quantum numbers ($n$, $l$, $m<em>l$, $m</em>s$)

• Orbital shapes (s, p, d, f)

• Electron configurations (full and noble gas notation)

• Valence electrons

• Periodic trends: atomic radius, ionization energy, electron affinity, electronegativity

• Ionic vs. covalent bonding

• Lewis structures

• Resonance structures

• Formal charge

• Bond polarity

• Molecular geometry (VSEPR theory)

• Electron geometry vs. molecular geometry

• Polar vs. nonpolar molecules

• Hybridization ($sp$, $sp^2$, $sp^3$, $sp^3d$, $sp^3d^2$)

• Sigma and pi bonds

Skills You Need:

• Calculate wavelength, frequency, or energy of light ($E = hc/\lambda$, $E = hf$)

• Assign quantum numbers to electrons

• Write complete and abbreviated electron configurations

• Identify valence electrons

• Predict periodic trends and compare elements

• Draw Lewis structures with lone pairs and bonds

• Draw resonance structures

• Calculate formal charge

• Determine electron geometry and molecular geometry using VSEPR

• Predict bond angles

• Determine if molecules are polar or nonpolar

• Identify hybridization of central atoms

• Count sigma and pi bonds

UNIT 3: UNDERSTANDING REACTIONS (30% of exam, ~12 questions)

Topics Covered:

• Molar mass calculations

• Mole conversions (grams $\leftrightarrow$ moles $\leftrightarrow$ molecules)

• Empirical formulas

• Molecular formulas

• Mass percent composition

• Writing chemical formulas (ionic compounds, polyatomic ions)

• Balancing chemical equations

• Types of reactions (precipitation, acid-base, redox)

• Solubility rules

• Oxidation states

• Identifying oxidizing and reducing agents

• Stoichiometry (mole-to-mole, mass-to-mass)

• Limiting reactants

• Excess reactants

• Theoretical yield, actual yield, percent yield

• Molarity

• Titrations

Skills You Need:

• Calculate molar mass of compounds

• Convert between grams, moles, and molecules

• Determine empirical formula from mass or percent data

• Determine molecular formula from empirical formula and molar mass

• Write formulas for ionic compounds with polyatomic ions

• Balance chemical equations

• Predict products of reactions

• Assign oxidation states

• Identify oxidizing and reducing agents

• Perform stoichiometric calculations using mole ratios

• Identify limiting reactant and calculate product formed

• Calculate theoretical, actual, and percent yield

• Calculate molarity ($M = mol/L$)

• Solve titration problems ($M<em>1V</em>1 = M<em>2V</em>2$ or with mole ratios)

UNIT 4: THERMOCHEMISTRY AND GASES (10% of exam, ~4 questions)

Topics Covered:

• Gas laws: Boyle's Law ($P<em>1V</em>1 = P<em>2V</em>2$)

• Charles's Law ($V<em>1/T</em>1 = V<em>2/T</em>2$)

• Gay-Lussac's Law ($P<em>1/T</em>1 = P<em>2/T</em>2$)

• Ideal Gas Law ($PV = nRT$)

• Kinetic Molecular Theory (KMT)

• Endothermic vs. exothermic reactions

• Enthalpy ($\Delta H$)

• Hess's Law

• State functions

• Heat capacity and specific heat

• Calorimetry ($q = mc\Delta T$)

Skills You Need:

• Apply Boyle's, Charles's, and Gay-Lussac's Laws

• Convert temperature to Kelvin ($K = \degree C + 273.15$)

• Use Ideal Gas Law to solve for P, V, n, or T

• Identify which gas law to use based on given information

• Recognize endothermic ($\Delta H > 0$) vs. exothermic ($\Delta H < 0$)

• Apply Hess's Law (manipulate equations: flip $\to$ change sign, multiply $\to$ multiply $\Delta H$)

• Calculate heat using $q = mc\Delta T$

MUST MEMORIZE

Polyatomic Ions:

• Nitrate ($NO_3^-$)

• Sulfate ($SO_4^{2-}$)

• Carbonate ($CO_3^{2-}$)

• Phosphate ($PO_4^{3-}$)

• Hydroxide ($OH^-$)

• Chlorate ($ClO_3^-$)

• Ammonium ($NH_4^+$)

Constants:

• Avogadro's number: $6.022 \times 10^{23}$

• $R = 0.08206 L \cdot atm/(mol \cdot K)$

Key Conversions:

• $K = \degree C + 273.15$

• $1 mL = 0.001 L$