CHE103 Study Guide Exam 2

CHE103 - Study Guide Exam 2

Course Overview

  • Focus on fundamental principles of chemistry, specifically atomic structures, periodic trends, chemical bonding, the mole concept, chemical reactions, thermodynamics, and intermolecular forces.

Unit 2: Atomic Structure and the Periodic Table

  • Examination Preparation: Students should be prepared to:

    1. Write Electron Configurations

    • Generate electron configurations for each element through atomic number 56.

    • Define: Valence Electrons in main-group (representative) elements. Understanding the impact of these electrons on chemical properties.

    1. Describe Periodic Trends

    • Explain periodic trends regarding:

      • Atomic Radius: The size of an atom, typically increasing down a group and decreasing across a period.

      • First Ionization Energy: The energy required to remove the outermost electron from a gaseous atom, increasing across a period and decreasing down a group.

      • Electronegativity: A measure of an atom's ability to attract electrons in a bond, generally increasing across a period and decreasing down a group.

    • Rank Elements based on these properties.

Unit 3: Chemical Bonding

  • Following Unit Completion: Students should be able to:

    1. Draw Lewis Dot Structures

    • Create correct Lewis dot structures for atoms in the representative/main-block elements as well as determine the number of valence electrons for main group elements.

    1. Electron Configurations for Noble Gas Status

    • Use electron configurations/Lewis structures to identify electrons gained or lost for noble gas configuration.

    • Define: Cation (positively charged ion) and Ion (atom or molecule with a net electric charge due to loss or gain of electrons).

    • Determine the ion symbol given the number of protons and electrons; also ascertain the number of protons and electrons from an ion symbol.

    • Assess if ions/atoms are isoelectronic (having the same number of electrons).

    1. Octet Rule Application

    • Use the octet rule to predict the ions formed in ionic compounds. This involves:

      • Determining the formula for an ionic compound when given ion symbols.

      • Finding ion symbols given the formula of an ionic compound.

    1. Naming Binary Ionic Compounds

    • Correctly name binary ionic compounds through provided chemical formula or ion symbols.

    • Conversely, determine the ionic compound formula from the name.

    1. Lewis Structures for Covalent Molecules

    • Draw accurate Lewis structures for covalent compounds.

    • Define: Typical number of covalent bonds that elements form in covalent/molecular compounds.

    1. Naming Binary Covalent Compounds

    • Memorize naming rules for binary covalent compounds and apply to name compounds from chemical formulas or vice versa.

    1. Lewis Structures for Polyatomic Ions

    • Draw correct Lewis structures for polyatomic ions, memorize common polyatomic ions and formulas in Table 3.5.

    • Determine the formal charge of individual atoms in these structures.

    1. Formulas for Ionic Compounds

    • Write formulas for ionic compounds including those with representative metals and polyatomic ions.

    • Inspect formulas given ion symbols/compound names and vice versa.

    1. Naming Binary Ionic Compounds with Polyatomic Ions

    • Follow naming conventions based on provided formulas and ion symbols.

    • Learn common polyatomic ions from Table 3.5.

    1. Determine Formula Weights

    • Calculate formula weights for ionic and molecular compounds in atomic mass units.

Unit 4: The Mole and Chemical Reactions

  • Learning Objectives: At the conclusion of Unit 4, students should competently:

    1. Convert Measurements

    • Convert between moles, grams, and atoms for elements and compounds.

    • Define: Mole, its significance, and demonstrate conversion practices:

      • Moles to atoms, atoms to moles.

      • Moles to mass and mass to moles.

    1. Calculate Percent by Mass

    • Calculate the mass percentage of elements in compounds from chemical formulas.

    • Utilize mass percentages for element quantity assessments.

    1. Balanced Chemical Equations

    • Write balanced equations for given reactions, adjusting coefficients for balance.

    1. Stoichiometry Calculations

    • Apply the mole concept for calculations involving stoichiometry from balanced equations, including:

      • Conversions between moles and grams of reactants/products.

      • Theoretical yield calculations.

      • Calculation of percent yields using actual and theoretical yield measurements.

    1. Classify Chemical Reactions

    • Differentiate reaction types such as:

      • Decompositions.

      • Combination reactions.

      • Single and double replacement reactions.

      • Combustion.

      • Identify redox reactions and their components:

        • Determine compounds/elements oxidized and reduced.

        • Ascertain oxidizing and reducing agents.

Unit 5: Thermodynamics and Intermolecular Forces

  • Concepts and skills to be covered in examination preparation are:

    1. Predict Molecular Geometries

    • Utilize VSEPR theory to anticipate geometries of molecules and polyatomic ions, assessing both electron-domain and molecular geometry.

    1. Classify Chemical Bonds

    • Use electronegativity values to determine bond types, recognizing:

      • Define: Non-polar, polar covalent, and ionic bonds.

      • Analyze electronegativity trends to predict bond polarity.

    1. Assess Molecular Polarity

    • Evaluate whether covalent molecules are polar or nonpolar based on molecular shapes and bond polarities.