Environmental Chemistry

Use chemistry to understand how human activities can affect the air we breathe, the water we drink, and the global properties of our atmosphere and oceans.

Teacher: Kelly Daumit

Description

Why is there so much smog in China? How can ozone pollution be a bad thing if we need the ozone layer to be thicker? Why is there lead in your tap water? How did arsenic end up in your rice?

This course will develop the skills necessary to think critically about the answers to these questions. We begin with a review of basic kinetics, thermodynamics, and chemistry. The next three weeks focus on the atmosphere, including the chemistry governing global climate change, destruction of the ozone layer, and formation of particulate matter, as well as address common misconceptions about atmospheric chemistry and climate change. The last two weeks will focus on aquatic chemistry, including acid pollution, heavy metals, and the partitioning of chemicals among soil, water, air, and biota.

Throughout the course we will highlight current research topics in these fields, including research being conducted at MIT. The structure of the course will be interactive lectures interspersed with in-class group work on problems or activities. As a mini-project, you will choose a special topic (for instance, an analytical instrument, research method, or scientific paper) and give a short presentation on the topic later on in the course.

Tentative list of topics covered

Structure and dynamics of the atmosphere, climate change, radiative balance, feedbacks, geoengineering, chemical composition, photochemistry, ozone, policy, chemical reactions, oxidation, particulate matter, acid-base chemistry, solubility, partitioning, soil chemistry, arsenic in ground water.

For the application...

Prerequisites

One year of high school chemistry, or equivalent knowledge.

Relevant experience

Please list the chemistry and environmental or Earth science courses you have taken. Indicate the level (e.g., regular, honors, AP, IB) and your grades in them. Also describe any activities, programs, or independent study you have done related to chemistry, environmental science or Earth science.

Core-specific application question

The application question for this class consists of multiple parts. You should provide responses to all parts. These are designed to require some thought, so don’t be discouraged if it takes you a while to come up with good answers. You can do it!

Part 1

Alpha-pinene (C₁₀H₁₆) is a gas emitted by pine trees. It can react with ozone (O₃, also a gas) to produce pinonaldehye (C₁₀H₁₆O₂). Assume 20% of alpha-pinene molecules get converted to pinonaldehyde molecules. Please show all work and list any assumptions as you answer the following questions:

(A) Hydrogen peroxide (H₂O₂) is also a product of the reaction. Write the balanced equation. You may also use water (H₂O) as a reactant or product.

(B) If 0.25 g of pinonaldehyde are measured in 1 cubic meter of forest air, how many grams of alpha-pinene were emitted per cubic meter of air in that forest?

(C) How many grams of ozone are used to create 1 gram of pinonaldehyde?

Part 2

Some of the products formed from reactions of alpha-pinene and ozone are less volatile (meaning they would rather be liquids or solids, not gases). These products condense to form small sub-micron particles (diameter less than one micrometer), called aerosol. Aerosol particles can remain suspended in the atmosphere for approximately two weeks. Describe all of the things that you think might happen to an aerosol particle during these two weeks. Be creative and descriptive; there are no wrong answers. We just want to see your thought process.