SOIL CHEMISTRY
INSTRUCTOR
Dr. ‘Mohammed Hashem’ Stietiya
Dept. of Land, Water and Environment
Faculty of Agriculture
University of Jordan
h.stietiya@ju.edu.jo
COURSE DESCRIPTION
The course applies principles of chemistry to the understanding of soil related properties and
processes including soil clay mineralogy, soil organic matter genesis and their properties,
mineral solubility, adsorption and desorption, ion exchange, oxidation and reduction, acidity,
and alkalinity. The course includes problem sets that expose students to practical situations of
soil contamination, degradation, contaminant transport, and release.
COURSE OUTLINE
 The Soil Environment
 Review of Chemistry Fundamentals
 Soil Mineralogy
o Chemical Bonds
o Soil Minerals
o Pauling’s Rules
o Structure of Clay Minerals
o Primary Soil Minerals
o Secondary Soil Minerals
o Source of Charges
o Oxides and Oxyhydroxides
o Mineral Weathering and Stability
 Soil Water Chemistry
o Review of Chemical Equilibrium
o Chemistry of Water
o Lewis Acids and Bases
o Hard-Soft Acid-Base Theory
o Colligative Properties
o Hydrolysis of Cations
o Distribution Diagrams
o Ion Speciation in Soil Solution
 Mineral Solubility
o Review of Laws of Thermodynamics
o Chemical Equilibrium and Free Energy of Reaction
o Ion Activity Product
o Saturation Index
o Stability Diagrams
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Adsorption
o Importance and Concepts
o Surface Functional Groups
o Surface Complexation
o Adsorption Isotherms
o Sorption of Anions and Cations
o Point of Zero Charge
o Adsorption Kinetics and Equilibria
Soil Organic Matter
o Genesis and Characteristics
o Fractionation of Humic Substances
o Functional Groups
o Structure of Soil Organic Matter
o Charge Characteristics
o Humic Substance Interaction with Metals
Oxidation-Reduction Reactions in Soils
o Importance and Concepts
o Redox Reactions in Soils
o Electrode Potential
o Equilibrium Constant and pE
o Free Energy and pE
o pE – pH diagrams
COURSE OBJECTIVES
The objectives of this course are to introduce students to chemical processes occurring in the soil
environment, to quantify those process and reactions, and to use the fundamentals of chemistry for
problem solving of practical situations.
REFERENCES
Essington, M.E. 2004, Soil and Water Chemistry: An Integrative Approach. CRC Press, Boca
Roton.
Sparks, D. L. 2003. Environmental Soil Chemistry. Acad. Press. New York.
GRADING
Two exams with a total of 25%
Problem sets in classroom and homework: 10%
Lab Work: 15%
Final Exam: 50%
EXAM SCHEDULE
First Exam
Second Exam
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