EARTH 131: Earth and Environmental Chemistry

Course description: Earth and Environmental Chemistry introduces the fundamental principles of chemistry for beginning students in Earth and Environmental Sciences and related programs, including Program in the Environment.  Solving any mystery about how our Earth works or solving any environmental challenge today requires some knowledge of chemistry.  Therefore, the goal of this course is to get all students excited about chemistry and its many applications to earth and environmental science.  The approach to achieve this objective is to help students identify the cross cutting concepts between chemistry and earth and environmental science, and to introduce students to the ways professional earth and environmental scientists actually use principles of chemistry to do their work.

Students will learn the same fundamental principles taught in an introductory college chemistry course including the states and properties of matter, chemical properties of elements, chemical stoichiometry, properties of gases, liquids, solids and solutions, atomic and molecular structure. The difference between this course and any introductory college-level general chemistry course is that the content is tailored to, and examples are drawn from, the earth and environmental sciences

EARTH 478: Introduction to Aquatic Geochemistry

Course description: The objective of this course is to develop an understanding of the chemical compositions of natural waters, emphasizing both chemical and biogeochemical processes operating near Earth’s surface; equilibrium vs. kinetic controls on chemical weathering; solute sources and mass balances in natural waters. Hands-on field and lab experience provides training in methods of applied geochemistry. From the syllabus: Water- H2O- is a unique molecule: it dissolves just about anything, it is sticky, and in solid form, it floats. These and other unique traits of water make life as we know it possible. But to solve age-old geologic mysteries and current environmental problems, we have to develop a much richer understanding of water on Earth. The reason is that water on Earth is not pure H2O; as water flows through Earth’s surface it dissolves many thousands of chemicals that make natural waters (e.g. streams, lakes, oceans, glaciers or ice cores) very different from pure H2O. And you know from everyday experiences that not all water is the same: some streams are crystal clear, while others are turquoise blue or golden brown. Some groundwater is classified as hard or doesn’t taste or smell good. Some lakes are very susceptible to contamination while others buffer against change. Water on Earth is so diverse because of the many thousands of chemicals dissolved in natural waters in tiny amounts, from gases like CO2 or CH4 or salts of carbonates or sulfides to trace metals like iron, lead or mercury to organic compounds like acetate or domoic acid. The diversity in the chemical composition of natural waters is what makes different streams, rivers, groundwaters, lakes or oceans distinct from each other. And it is the interactions among all the chemicals in water that largely control what happens in water. Sorting out these interactions is what geochemists to do unravel the secrets of past climates trapped in frozen water, or to predict what water is safe to drink, for example. To understand what happens in water, we have to first start by learning what controls the amounts and forms of all the major chemicals present in natural waters. Luckily, the chemical composition of natural waters on Earth is not random; concentrations and forms of chemicals are governed by the laws of thermodynamics and kinetics. In this class we focus on the thermodynamic controls (i.e. equilibrium) on concentration and speciation of acids and bases, major and minor metals, and organic compounds in natural waters.