Examination of Water and Wastewater 5210 BIOCHEMICAL OXYGEN DEMAND (BOD)*#(1) 5220 CHEMICAL OXYGEN DEMAND (COD)*#(2) 5220 A. Introduction Chemical oxygen demand (COD) is defined as the amount of a specified oxidant that reacts with the sample under controlled conditions. The quantity of oxidant consumed is expressed in terms of its oxygen equivalence. Because of its unique chemical properties‚ the dichromate ion (Cr2O72–) is the specified oxidant in Methods Section 5220B‚ Section
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deals with matter‚ its composition‚ and changes they undertake. Chemistry has been part in our lives ever since. It contributes to our existence‚ our culture‚ and our life. Chemistry explains why changes happen around us. All living processes are chemical reactions. It helps in sustaining our needs. Through this we are able to feed the world’s population‚ medicines to cure diseases and improve health‚ and to protect our environment. Chemistry plays an important role in our lives. It contributes
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This experiment was performed to demonstrate a cycle of chemical reactions involving copper. This lab will start with copper as a reactant in the first reaction through a series of five chemical forms of aqueous phase reactions and ending to calculate the percentage of recovered solid copper as a product in the last reaction of the experiment. The experiment resulted in a percent recovery from the cycle of copper reactions of an increase to 139%. . Introduction: The purpose of this experiment is
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Report on TREATMENT AND DISPOSAL OF CHEMICAL WASTES IN CHEM 111.1 PHYSICAL CHEMISTRY LABORATORY Submitted by: Christian Manahan Anna Esperanza Legaspi CHEM 180 – X 2nd Semester AY 2012-2013 Date Presented: March 21‚ 2013 Date Submitted: March 22‚ 2013 Prof. Josefina L. Solivas I. Introduction Chemicals have been indispensable in the everyday lives of humans. Their uses have made life easier and better. However‚ their effects on the environment have been accumulating and
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Chemistry Summary The particle theory: 1. Matter is made of tiny particles 2. Particles of matter are in constant motion 3. Particles of matter are held together by very strong electric forces 4. There are empty spaces between the particles of matter that are very large compared to the particles themselves. 5. Each substance has unique particles that are different from the particles of other substances 6. Temperature affects the speed of the particles. The
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A Chemical change is any change that results in the formation of a new chemical substance. It is something that everyone learns about in school‚ but never really tries to see it in the real world. We all know the basic examples; baking a cake‚ burning wood… etc. What about the examples that are happening around us. For example‚ the Statue of Liberty has been through a chemical change. It was first a dull brown color‚ and now it is a green color. That happened due to a chemical change. During the
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CHEM 1105 Experiment 4: Determination of a Chemical Formula Introduction When atoms of one element combine with those of another‚ the combining ratio is typically an integer or a simple fraction. The simplest formula of a compound expresses that atom ratio. When two or more elements are present in a compound‚ the formula still indicates the atom ratio. To find the formula of a compound we need to find the mass of each of the elements in a weighed sample of that compound. For example‚
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Lab #5 Chemical Reactions & Balancing Equations Objectives Observe and classify several chemical and physical changes. Give evidence for the occurrence of a chemical reaction. Write a balanced equation for a chemical reaction. Identify a reaction as a combination‚ decomposition‚ replacement‚ or combustion reaction. Background Physical properties can be observed without changing the chemical composition of the substance. Common physical properties that can be measured without changing the chemical
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Chemical Imbalance and Depression Melissa Creamer PSYC 3002- Developing a Psychology Perspective Project Draft - Persuasive Paper Capella University mcreamer@capellauniversity.edu October 2012 Introduction According to some Psychologists‚ chemical imbalance can lead to depression and other mental illnesses. It is very unclear that depression is one of the possible symptoms of a chemical imbalance. However‚ chemical imbalance doesn’t lead to every kind of depression seen in the lives of
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Data Tables: Part 1: |Chemicals|Well No.|Observations of the Reaction| A.|NaHCO3 + HCl||Bubbling in center of droplets. Homogeneous| B.|HCl + BTB||Turns yellow immediately after contact. Homogeneous| C.|NH3 + BTB||Turned dark blue. Homogeneous| D.|HCl + blue dye||Solution turns green immediately after contact. Homogeneous| E.|Blue dye + NaOCl||Stays blue. Homogeneous| | with the 1 drop of HCl||Mixes and turns a bluish green color. Homogeneous| F.|NaOCl + KI||Slightly yellowish tint to the
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