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Environmental Chemistry

Environmental Chemistry is the examination of biochemical phenomena that occur in natural environments. Its primary focus is on the properties of certain chemicals found in the air, soil and water. Although it studies how the uncontaminated environment works, by analyzing aspects such as natural concentrations of different chemical substances, it also takes into account the effects of human activity in each of these environments.

 

Important concepts are drawn from other Chemistry disciplines, such as chemical reactions, solubility and different analytical techniques. These concepts are then applied to specific environmental topics, such as contaminants, radiochemicals and environmental indicators, to better understand the underlying chemistry behind these phenomena.

For example, there are many chemical indicators which can be measured independently or in conjunction to assess the quality of water. The level of oxygenation, or the pH, or both of these measurements can be measured to assess whether for example, the water in a certain lake is suitable for habitation of a certain species, or whether it is in fact hazardous and sub-optimal.

Environmental Chemistry is becoming increasingly important as many Environmental Agencies use its concepts and techniques for the detection and identification of pollutants, such as heavy metal contamination from nearby industries, or urban runoff from a nearby city. Thus, although many of the concepts are drawn from different Chemistry disciplines, it focuses more on the properties of chemicals in its natural context.

Categories within Environmental Chemistry

Hazardous Materials

Postings: 28

A Hazardous Material is one that presents a risk to health or the environment.

Using TLC to Identify Compounds

The solvent used for A :Cyclohexane:chloroform (75:25) The solvent Used for B: Ethyl ether:acetone (70:30). how can I mix solvent would you try next and explain why based on the two sets of results? what have to do to confirm the identity of these spots?

Making up a standard reference solution for HPLC

How can I make up 100ml of a solution containing Compound A (solid, purity of 83.7%) at 90 ug/ml and compound B (liquid, density of 1.12 and purity of 90.5%) at 30 ug/mL for HPLC reference standard? Please write all the steps for making this solution. The solvent is 0.1M H2PO4 in 75% methanol.

Impeller-powered Flocculation Basin

8.7 Step-wise solution to a numerical problem related to a flocculation-based water treatment plant having a flow of 25 MGD. The plant is to employ alum coagulation, and pertinent data for the flocculation basin are as follows: detention time = 20 min, G = 35 sec^-1 (at 50 degrees Fahrenheit), GT = 10,000 to 100,000, width = 1.2

Groundwater Hardness - EDTA Titration

Hardness in groundwater is due to the presence of metal ions, primarily Mg2+ and Ca2+. Hardness is generally reported as ppm CaCO3 or mmol/L Ca2+. To measure the water hardness, a sample of groundwater is titrated with EDTA, a chelating agent; in the presence of the indicator eriochrome black T, symbolized as In. Eriochrome bl

Determining groundwater hardness

Question 1: Hardness in groundwater is due to the presence of metal ions, primarily Mg2+ and Ca2+. Hardness is generally reported as ppm CaCO3 or mmol/L Ca2+. To measure the water hardness, a sample of groundwater is titrated with EDTA, a chelating agent; in the presence of the indicator eriochrome black T, symbolized as In. Er

Photorespiration

Photorespiration is considered a wasteful process that decreases the growth of C3 plants. What experiment would you propose to minimize the role of photorespiration in plants and ideally see increased growth as a result? Provide a brief description of your experiment and how you could carry out the experiment in laboratory condi

Density of Air

The density of air at ordinary atmospheric pressure and 25 0C is 1.19 g/L. What is the mass of air, in kg, in a room that measures 12.5 ft by 15.5 ft by 8.0 ft? Please provide a detailed explanation.

Chemistry: A gas originally occupies 20L at 24.7 psia and 5 C. What would the pressure be if the volume changed to 4.77ft3 and the temperature was 82 F? Give the answer in atmospheres.

Please show all work and steps to following: 11. In the welding shop of the XYZ Manufacturing plant you have a cylinder with a volume of 548L of a compressed gas, and the pressure gauge shows 238 psig at the room temperature 25 C. A welder was instructed to go outdoors to weld, and the temperature in Texas at this time was

Describe the nature and characteristics of PCB's.

Describe the nature and characteristics of PCB's. Why are they of importance to an EH&S or FS professional who encounters them when coming upon an incident scene where they are present? What precautions, or actions, should the EH&S or FS professional take when faced with this situation? What happens to FS personnel and their tur

Chemistry of Hazardous Compounds

Acetyl chloride is a colorless, fuming liquid used primarily in the chemical industry. a) How is acetyl chloride produced? If 915 gallons is produced and shipped, will DOT require the carrier to display the flammable placard? Explain your answer. b) When there is a bulk spill of this chemical, why is it necessary to prev

CFC's and the Ozone Layer for Chemistry Students

What is ozone and how it works as a protective molecule for our environment? What are the effects of CFCs on the ozone layer? What other alternatives you can think of to diminish environmental impact of CFCs? Draw the electron dot structure of ozone, and explain its molecular shape and properties. Is ozone a covalent

Preparation of an a,B unsaturated ketone via michael and aldol condensation

I'm wondering if you could help me answer a few questions about a lab I'm doing. We are preparing an a,b-unsaturated ketone via Michael and aldol condensation reactions. The reactants are trans-chalcone and ethyl acetoacetate (in ethanol and NaOH). This creates 6-ethoxycarbonyl-3,5-diphenyl-2-cyclohexenone. 1) A white so

Help urgent as well

Please I answered all of them except b, therefore, I need help with answer b and also could you verify my answers please for a, c, and d? if they are wrong what would it be? Thank you -The pH of uncontaminated rain water is about 5.6. The pH of rain falling in Cleveland, OH is 4.2 and that in Omaha, NE is 5.5. a. In wh

Chemistry of 911

Can anyone explain to me the chemistry behind the fires that brought down the Twin Towers? Please provide links to your references.

Environmental Chemistry questions

1. A) Draw the Lewis structure of chlorine nitrate. b) Write out the chemical equations showing how chlorine nitrate is formed in the stratosphere and for the reactions that convert it back to active chlorine compounds. Include reactions that occur in polar stratospheric clouds. Calculate the rate constants at

Resources PowerPoint - Greenhouse effect and Ozone Layer

'Resources' PowerPoint -Visually stunning, animated presentation explaining : 1. The Greenhouse Effect - how the sun's visible light is converted into trapped infra red light and heat, causing the planet to warm up. 2. The Ozone layer - what is Ozone? where is the Ozone layer? How does it protect us from harmful UV light.

Chemistry Practice Problems

1) Free radicals (see Problem 115) are also important in many environmentally significant reactions. For example, photochemical smog, which forms as a result of the action of sunlight on air pollutants, is formed in part by the following two steps. X NO2 NO O O O2 O3 UV light Ozone damages rubber products. The product of this re

Cycling of Calcium in Nature

Please review the occurrence and cycling of calcium in nature, along with its use. Analyze and evaluate the article as to it's contemporary relevance regarding the elements availability, health implications and environmental impact.

Why no lubrication on oxygen tank?

Why do suppliers of compressed oxygen warn their customers to refrain from lubricating the values, regulaters, gauges, and fittings associated with oxygen storage containers?

Calculating kWh of a wind turbine

Assume a wind turbine with a hub 50 meters above the ground, a rotor diameter of 60 meters and a wind-conversion efficiency of 25 percent. The turbine operates in an area with an average wind-power density of 700 watts/sq meter at 50 meters altitude. How much electricity (kwH) can the turbine generate per year? Wind densitie

Reaction between glucopyranose unit and ammonium hydroxide

We are asked to determine the reaction and final chemical structure of when a glucopyranose unit is reacted with ammonium hydroxide? CH2OH + NH4OH = ?? 1) What does the final reaction structure look like? 2) Would this be referred to as "cat-ionizing" this unit?

Mass of Calcium Carbonate and pH of Lake Water

The pH in a lake the size of 4.0 km X 7.0 km and an average depth of 100 m is found to be 4.5. Calculate the mass of calcium carbonate that must be added to the lake water in order to raise its pH to 6.0, assuming the reaction of H+ with CaCO3 gives CO2 here (answer in grams). Hint: Calculate volume of lake, change of H+ conc