Essential Tables, Formulas, and Concepts for Introductory Chemistry

Measurement and Problem Solving

Length, Volume, and Mass Conversions

Understanding unit conversions is fundamental in chemistry for accurate measurement and calculation. The following tables provide common conversion factors for length, volume, and mass.

Length	Conversion
1 kilometer (km)	1,000 m
1 meter (m)	100 cm
1 centimeter (cm)	10 mm
1 mile (mi)	1.609 km
1 yard (yd)	0.9144 m
1 foot (ft)	30.48 cm
1 inch (in)	2.54 cm

Volume	Conversion
1 liter (L)	1,000 mL
1 milliliter (mL)	1 cm3
1 gallon (gal)	3.785 L
1 quart (qt)	0.946 L
1 pint (pt)	0.473 L
1 fluid ounce (fl oz)	29.57 mL

Mass	Conversion
1 kilogram (kg)	1,000 g
1 gram (g)	1,000 mg
1 pound (lb)	453.6 g
1 ounce (oz)	28.35 g

Energy Conversion Factors

Energy is commonly measured in joules (J) and calories (cal). The following conversion factors are useful:

• 1 calorie (cal) = 4.184 J

• 1 Calorie (Cal) = 1,000 cal

• 1 kilowatt-hour (kWh) = 3.60 × 106 J

Atoms, Elements, and Ions

Common Ions and Polyatomic Ions

Chemistry involves understanding the charges and formulas of ions. Below are tables of common ions and polyatomic ions.

Ion Name	Symbol	Ion Formula
Sodium	Na	Na+
Potassium	K	K+
Calcium	Ca	Ca2+
Chloride	Cl	Cl-
Iron(II)	Fe	Fe2+
Iron(III)	Fe	Fe3+

Polyatomic Ion	Formula	Charge
Ammonium	NH4+	+1
Nitrate	NO3-	-1
Sulfate	SO42-	-2
Phosphate	PO43-	-3

Chemical Composition and Reactions

Solubility Rules for Ionic Compounds in Water

Solubility rules help predict whether an ionic compound will dissolve in water. The following table summarizes key rules:

Ion	Solubility Rule
Na+, K+, NH4+	All compounds are soluble
NO3-, C2H3O2-	All compounds are soluble
Cl-, Br-, I-	Soluble except with Ag+, Pb2+, Hg22+
SO42-	Soluble except with Ba2+, Pb2+, Ca2+, Sr2+
CO32-, PO43-	Insoluble except with Na+, K+, NH4+
OH-	Insoluble except with Na+, K+, Ba2+

Electrons in Atoms and the Periodic Table

Electromagnetic Spectrum

The electromagnetic spectrum includes all types of electromagnetic radiation, from radio waves to gamma rays. Visible light is a small part of this spectrum.

• Wavelength ($\lambda$) and frequency ($\nu$) are inversely related: $c = \lambda \nu$

• Energy of a photon: $E = h \nu$

• Visible light ranges from approximately 400 nm (violet) to 700 nm (red).

The Periodic Table of the Elements

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

• Groups (columns) share similar valence electron configurations.

• Periods (rows) indicate increasing principal energy levels.

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

Chemical Bonding and Molecular Geometry

Electron Domains and Molecular Shapes (VSEPR Theory)

The Valence Shell Electron Pair Repulsion (VSEPR) theory predicts the shapes of molecules based on the number of electron domains around the central atom.

Electron Domains	Bonding Pairs	Lone Pairs	Electron Geometry	Molecular Geometry	Bond Angle	Example
2	2	0	Linear	Linear	180°	CO2
3	3	0	Trigonal planar	Trigonal planar	120°	BF3
3	2	1	Trigonal planar	Bent	~120°	SO2
4	4	0	Tetrahedral	Tetrahedral	109.5°	CH4
4	3	1	Tetrahedral	Trigonal pyramidal	~107°	NH3
4	2	2	Tetrahedral	Bent	~104.5°	H2O
5	5	0	Trigonal bipyramidal	Trigonal bipyramidal	90°, 120°	PCl5
6	6	0	Octahedral	Octahedral	90°	SF6

Key Chemical Formulas and Equations

Fundamental Equations in Chemistry

Below are essential formulas used in introductory chemistry:

• Temperature conversion: $K = ^\circ C + 273.15$

• Density: $d = \frac{m}{V}$

• Atomic mass (weighted average): $\text{Atomic Mass} = \sum (\text{fractional abundance of isotope}_i \times \text{mass of isotope}_i)$

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

• Mass percent of element in compound: $\text{mass percent of element X} = \frac{\text{mass of element X in 1 mol of compound}}{\text{mass of 1 mol of compound}} \times 100\%$

• Mole concept: $\text{moles} = \frac{\text{mass}}{\text{molar mass}}$

• Empirical formula: $\text{molecular formula} = n \times \text{empirical formula}$, where $n = 1, 2, 3, ...$

• Gas law: $PV = nRT$

• Partial pressure: $P_A = X_A P_{\text{total}}$

• Concentration: $M = \frac{n}{V}$

• Mass percent in solution: $\text{mass percent} = \frac{\text{mass solute}}{\text{mass solution}} \times 100\%$

Additional info:

• Some context and examples have been inferred to ensure completeness and clarity for introductory chemistry students.

• All tables have been reconstructed and summarized for clarity and academic usefulness.