Essential Reference Sheet for GOB Chemistry: Periodic Table, Formulas, and Solubility Rules

Periodic Table of Elements

Overview

The Periodic Table of Elements is a systematic arrangement of all known chemical elements, organized by increasing atomic number. It is a foundational tool in chemistry, providing essential information about each element, including its symbol, atomic number, and atomic mass.

• Groups (Columns): Elements in the same column share similar chemical properties due to their valence electron configurations.

• Periods (Rows): Elements in the same row have the same number of electron shells.

• Element Information: Each box contains the element's symbol, atomic number, and atomic mass.

• Classification: Elements are classified as metals, nonmetals, and metalloids based on their properties.

Example: Sodium (Na) is in Group 1 (alkali metals), Period 3, with atomic number 11.

Reference Formulas and Constants

Key Chemical Formulas

These formulas are essential for calculations in general, organic, and biochemistry (GOB Chemistry).

• Concentration (C): $C = \frac{n}{V}$, where n is moles and V is volume in liters.

• pH and pOH: $\text{pH} = -\log[\text{H}^+]$ $\text{pOH} = -\log[\text{OH}^-]$

• Relationship between pH and pOH: $\text{pH} + \text{pOH} = 14$

• Water Dissociation Constant: $K_w = [\text{H}^+][\text{OH}^-] = 1.0 \times 10^{-14}$

Example: If $[\text{H}^+] = 1.0 \times 10^{-7}$ M, then $\text{pH} = 7$.

Avogadro's Number and Conversion Factors

• Avogadro's Number: $6.022 \times 10^{23}$ particles/mol

• Mole-Mass Conversion: $\text{mass (g)} = \text{moles} \times \text{molar mass (g/mol)}$

Solubility Rules

General Guidelines for Solubility in Water

Solubility rules help predict whether an ionic compound will dissolve in water. These rules are crucial for understanding precipitation reactions and solution chemistry.

Ion	Solubility	Exceptions
Group 1 ions (Li+, Na+, K+, etc.)	Soluble	None
NH4+ (ammonium)	Soluble	None
NO3- (nitrate), C2H3O2- (acetate)	Soluble	None
Cl-, Br-, I-	Soluble	Ag+, Pb2+, Hg22+
SO42- (sulfate)	Soluble	Ba2+, Pb2+, Ca2+, Sr2+
CO32-, PO43-	Insoluble	Group 1 ions, NH4+
OH-	Insoluble	Group 1 ions, NH4+, Ba2+

Example: NaCl is soluble in water, while AgCl is insoluble.

Carbon Chain Prefixes

Naming Organic Compounds

Organic compounds are named based on the number of carbon atoms in their longest continuous chain. The following prefixes are used:

Number of Carbons	Prefix
1	meth-
2	eth-
3	prop-
4	but-
5	pent-
6	hex-
7	hept-
8	oct-

Example: CH4 is methane, C2H6 is ethane.

Structural Formulas for Organic Compounds

Common Organic Functional Groups

Organic molecules are classified by their functional groups, which determine their chemical reactivity and properties.

Number of Carbons	Structural Formula
1	CH4 (methane)
2	CH3CH3 (ethane)
3	CH3CH2CH3 (propane)
4	CH3CH2CH2CH3 (butane)

Example: The structure of propane is CH3CH2CH3.

Summary Table: Essential Reference Data

Purpose

This table summarizes the most important constants and conversion factors for GOB Chemistry calculations.

Constant/Factor	Value
Avogadro's Number	6.022 × 1023 particles/mol
Water Dissociation Constant ($K_w$)	1.0 × 10-14
pH + pOH	14

Additional info: These reference sheets are designed for CHEM 1000-level GOB Chemistry courses and are suitable for exam preparation and quick review of essential concepts.