EXPERIMENT 11: DETERMINATION OF DISSOLVED OXYGEN IN A WATER SAMPLE (WINKLER METHOD) INTRODUCTION In an alkaline solution‚ dissolved oxygen will oxidize manganese(II) to the trivalent state. 8OH-(aq) + 4Mn2+(aq) + 2H2O(l) －－＞ 4Mn(OH)3(s) The analysis is completed by titrating the iodine produced from potassium iodide by manganese(III) hydroxide. 2Mn(OH)3(s) + 2I-(aq) + 6 H+(aq) －－＞ 2Mn2+(aq) + I2(aq) + 6H2O(l) Sodium thiosulphate is used as the titrant. Success of the method is critically
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Electricity and Magnetism Electricity Circuit symbols Potential difference The energy which is delivered to an electric circuit comes from the supply. The greater the potential difference of the power supply the more energy is delivered. Potential difference is measured in volts‚ which has the unit symbol V. Cells in series The more chemical cells that are connected in series the greater the potential difference that they supply. The potential difference of a number of cells connected
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Chapter 3 Financial Statements‚ Cash Flow‚ and Taxes Learning Objectives After reading this chapter‚ students should be able to: ◆ Briefly explain the history of accounting and financial statements‚ and how financial statements are used. ◆ List the types of information found in a corporation’s annual report. ◆ Explain what a balance sheet is‚ the information it provides‚ and how assets and claims on assets are arranged on a balance sheet. ◆ Explain what an income statement
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letters of a word. 2. An example of a plain language search is D. How do I change a flat tire? 3. NoodleTools is a website that B. provides educational tools‚ software‚ and information for students. 4. Using a minus (-) sign in your search indicates that B. the word should be excluded from your search. 5. Examples of common search engines used for research include B. Google‚ Bing‚ and Yahoo. 6. Which of the following questions do you not need to ask in order to help determine the suitability of a
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Chapter 4 1. If you invest $1000 today at an interest rate of 10% per year‚ how much will you have 20 years from now‚ assuming no withdrawals in the interim? SOLUTION: n PV FV PMT Result 20 2. i 10 1000 ? 0 FV =6‚727.50 a. If you invest $100 every year for the next 20 years‚ starting one year from today and you earn interest of 10% per year‚ how much will you have at the end of the 20 years? b. How much must you invest each year if you want to have
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Guided Reading Questions: Chapters 3 and 4 These questions are meant to serve as guide to help you pick out the most important information. Answer these questions to the best of your ability. Bulleted lists are acceptable as long as they consist of more than a few words. These concepts should be well thought out. Chapter 3 “Introduction” “Global Competition and the Expansion of England’s Empire” “Origins of American Slavery” “Colonies in Crisis”- Choose only one sub-topic “The Growth of
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If i were to boil different liquids i would get many different results. But that is the whole point. With many of the liquids i will be trying they will be varying in density and other things. As far as i know water would seem to boil faster. As it has a boiling point of 212 degrees fahrenheit. That is just the boiling point of the water with nothing else. But when you boil different things with other stuff like sugar and where acidity levels are different you get other results. It may boil slower
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Domaradzki Labs 3 & 4 09/19/11 Objective: In steam distillation lab (lab 3)‚ we must obtain pure Eugenol from cloves through the process of steam distillation. In the crystallization lab (lab 4) part 1‚ we must acquire the best possible pure crystallization of acetylsalicylic acid from aspirin and in part 2 we must obtain a similar pure crystallization of benzil from an impure mixture of benzil. Materials: In lab 3‚ we used 75 g of cloves from which we must extract Eugenol. Water was largely
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2: Separation of a Mixture of Solids Purpose: This experiment allowed me to learn different separation techniques for various substances based on their specific chemical properties. Procedure: I began this experiment by using a magnet to pick up and collect the iron filings out of the mixture. Then the sand was separated by placing the mixture into a beaker and boiling it in distilled water in order to dissolve the salt and benzoic acid‚ once boiling the liquid was poured out leaving the sand
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PURPOSE The purpose of this experiment is to become familiar with the separation of mixtures of solid and learn separation techniques based on the chemical properties of a substance. PROCEDURES 1. Separating out the Iron a. Use your digital scale to determine the mass of your weighing dish. b. Empty the entire mixture of solids from the plastic bag into the weighing dish and determine the gross mass of the total mixture and weighing dish. Compute the net mass of the mixture: this is equal
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