CHEM 103 Final Exam Comprehensive Study Guide

Introduction to Chemistry

Key Concepts and Reference Data

This guide provides essential reference information and formulas for introductory college chemistry, including atomic structure, chemical reactions, the periodic table, and important constants and equations.

The Metric System and Unit Conversions

Common Conversions and Constants

• Avogadro’s Number: $6.02 \times 10^{23}$ atoms, molecules, or formula units per mole.

• Molar Volume of Gas at STP: 1 mol gas = 22.4 L (at 0°C and 1 atm).

• Molar Mass: 1 mol = molar mass (g/mol).

• Temperature Conversions:

  • Celsius to Kelvin: $K = ^\circ C + 273$

  • Fahrenheit to Celsius: $^\circ C = \frac{(^\circ F - 32)}{1.8}$

  • Celsius to Fahrenheit: $^\circ F = 1.8 \times ^\circ C + 32$

Matter and Energy

Density and Percent Composition

• Density: $\text{Density} = \frac{\text{mass}}{\text{volume}}$

• Percent Composition: $\text{Percent} = \frac{\text{one quantity}}{\text{total sample}} \times 100$

Models of the Atom

Electron Configuration

Electron configuration describes the arrangement of electrons in an atom’s orbitals. The order of filling is based on increasing energy levels.

• Order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p

The Periodic Table

Element Classification and Trends

The periodic table organizes elements by increasing atomic number and groups elements with similar chemical properties.

• Groups: Vertical columns (e.g., Group 1A: Alkali metals, Group 2A: Alkaline earth metals).

• Periods: Horizontal rows.

• Metals, Nonmetals, Metalloids: Metals are on the left, nonmetals on the right, and metalloids border the staircase line.

Electronegativity Trends

Electronegativity increases across a period (left to right) and decreases down a group (top to bottom).

Language of Chemistry

Common Polyatomic Ions

Polyatomic ions are ions composed of two or more atoms covalently bonded, carrying a net charge. Memorizing common polyatomic ions is essential for naming and writing chemical formulas.

Cation	IUPAC Name
NH4+	ammonium ion

Anion	IUPAC Name
C2H3O2-	acetate ion
CO32-	carbonate ion
ClO3-	chlorate ion
ClO2-	chlorite ion
CrO42-	chromate ion
CN-	cyanide ion
Cr2O72-	dichromate ion
HCO3-	hydrogen carbonate ion
HSO4-	hydrogen sulfate ion
OH-	hydroxide ion
NO3-	nitrate ion
NO2-	nitrite ion
ClO4-	perchlorate ion
MnO4-	permanganate ion
PO43-	phosphate ion
SO42-	sulfate ion
SO32-	sulfite ion

Greek Prefixes for Binary Molecular Compounds

Greek prefixes are used to indicate the number of atoms of each element in binary molecular compounds.

Atoms	Prefix	Atoms	Prefix
1	mono-	6	hexa-
2	di-	7	hepta-
3	tri-	8	octa-
4	tetra-	9	nona-*
5	penta-	10	deca-

Chemical Reactions

Activity Series for Metals

The activity series ranks metals by their reactivity in single-replacement reactions. A metal can replace any metal below it in the series from a compound.

• Order (most to least reactive): Li > K > Ba > Sr > Ca > Na > Mg > Al > Mn > Zn > Fe > Cd > Co > Ni > Sn > Pb > (H) > Cu > Ag > Hg > Au

Solubility Rules for Ionic Compounds

Solubility rules help predict whether an ionic compound will dissolve in water.

• Ionic compounds containing alkali metal ions or ammonium ion are soluble.

• Acetate, nitrate, and most halide and sulfate salts are soluble (with exceptions).

• Carbonates, chromates, phosphates, sulfides, and hydroxides are generally insoluble (with exceptions).

The Mole Concept

Stoichiometry and Percent Yield

• Percent Yield: $\text{Percent Yield} = \frac{\text{actual yield}}{\text{theoretical yield}} \times 100\%$

Chemical Equation Calculations

Unit Analysis Map

Unit analysis (dimensional analysis) is used to convert between units using conversion factors.

• Set up a chain of conversion factors to cancel units and solve for the desired quantity.

Gases

Gas Laws and Pressure Units

• Boyle’s Law: $P_1V_1 = P_2V_2$ (at constant T and n)

• Charles’s Law: $\frac{V_1}{T_1} = \frac{V_2}{T_2}$ (at constant P and n)

• Gay-Lussac’s Law: $\frac{P_1}{T_1} = \frac{P_2}{T_2}$ (at constant V and n)

• Combined Gas Law: $\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2}$

• Ideal Gas Law: $PV = nRT$

• Gas Constant (R): 0.0821 L·atm/mol·K or 62.4 L·mmHg/mol·K

• Dalton’s Law of Partial Pressures: $P_{\text{total}} = P_1 + P_2 + P_3 + \ldots$

Units of Gas Pressure

Unit	Standard Pressure
atmosphere	1 atm (exactly)
inches of mercury	29.9 in. Hg
centimeters of mercury	76 cm Hg (exactly)
millimeters of mercury	760 mm Hg (exactly)
torr	760 torr (exactly)
pounds per square inch	14.7 psi
kilopascal	101 kPa

Models of the Atom and Electromagnetic Spectrum

Energy Levels and Electron Transitions

Electrons occupy specific energy levels. Transitions between these levels involve absorption or emission of energy as electromagnetic radiation.

Order of Orbital Filling

The order in which electrons fill atomic orbitals is determined by the Aufbau principle, which fills lower energy orbitals first.

Additional Reference Tables

Periodic Table with Common Ions

This table highlights the most common ionic charges for main group elements and transition metals.

*Additional info: This guide covers all major topics relevant to an introductory chemistry course, including atomic structure, periodic trends, chemical nomenclature, stoichiometry, gas laws, and solution chemistry. The included tables and diagrams are essential for quick reference and exam preparation.*