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自然科學 大學

為什麼[A(org)]=n[An(org)]成立 (第三張圖equation 7.9) 感謝

Experiment 7 Experiment 7 The partition of Organic acid between Water and Organic solvent Objectives Understand the partition of a solute between two immiscible solvents. Introduction A chemical analysis that is performed primarily with the aid of volumetric glassware (e.g., pipets, burets, volumetric flasks) is called a volumetric analysis. For a volumetric analysis procedure, a known quantity or a carefully measured amount of one substance reacts with a to-be-determined amount of another substance with the reaction occurring in aqueous solution. The volumes of all solutions are carefully measured with volumetric glassware. The known amount of the substance for an analysis is generally measured and available in two ways: 1. As a primary standard: An accurate mass (and thus, moles) of a solid substance is measured on a balance, dissolved in water, and then reacted with the substance being analyzed. 2. As a standard solution: A measured number of moles of substance is present in a measured volume of solution - a solution of known concentration, generally expressed as the molar concentration (or molarity) of the substance. A measured volume of the standard solution then reacts with the substance being analyzed. The reaction of the known substance with the substance to be analyzed, occurring in aqueous solution, is generally conducted by a titration procedure. The titration procedure required a buret to dispense a liquid, called the titrant, into a flask containing the analyte. A reaction is complete when stoichiometric amounts of the reacting substances are combined. In a titration this is the stoichiometric point. In this experiment the stoichiometric point for the acid-base titration is detected using a phenolphthalein indicator. Phenolphthalein is colorless in an acidic solution but pink in a basic solution. The point in the titration at which the phenolphthalein changes color is called the endpoint of the indicator. Indicators are selected so that the stoichiometric point in the titration coincides (at approximately the same pH) with the endpoint of the indicator.

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數學 高中

根本看不懂啦\( ̄▽ ̄;)/

Your report should follow these guidelines, although you may choose how you present it: How to Write a Mathematics Report In writing your report, remember that you are writing up a mathematical story and so, like all good stories, it will need a beginning, a middle and an end. More formally, the main components of this writing style are: Introduction, Formulating the Problem, Solving the problem, Discussion of Results, and Conclusion. We will now consider some of the detail in each of these aspects. Introduction This is the beginning of the story. Give a brief explanation of what the problem is about what the goals of the report are and what will be presented. Assume that your reader does not know what the problem is about or how to solve it. Formulating the problem Translate the situation into a maths problem. Explain how you will begin to solve the problem and break it into simpler stages. Discuss any assumptions made. What quantities are variables and which values are fixed? You may use sub-headings if they assist you. Solving the Problem Show any calculations and mathematical reasoning that you use. (Assume that your reader does not know much maths). Do not show the same types of calculations repetitively. Just give one or two examples of a calculation and then put the rest of the results in a table. Use diagrams or graphs if they assist you. Make general remarks about what you observe in your calculation results and, possibly, why. You may want to criticise your work and go on to improve it in the next section. Explain what you will do next and why. Discussion of Results - Evaluate and Verify Summarise your results if necessary and refer to your mathematical reasoning. Justify procedures used. Interpret your results. First, are they reasonable or does something not look right and need further investigation or checking? Is there a decision to be made? Here is where you should present the decision-making process. Evaluate the strengths and limitations of your solutions. Conclusion Summarise your findings. Refer to the problem outlined in the introduction. Make sure that you answer the question that was asked. Make recommendations. No new material should be presented here.

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英文 高中

請問第五題 serve as是當作的意思吧?? 放這裡好怪誒😂😂 感謝!!

上 (A) 【97 北聯】醫療/健康:大笑有助身體健康 Laugh your head of ItS strong medicine, research _I act is good for you, says William Fry, professor_emeritus at Stanford mivbrsity and pioneer in laughter research. It increasesrblood /光 _)and contracts iorpiaal_ muScleS. A hundred belly ]aughs is the aerobic edulvalefmt 于防記 ten minuit arowlng machine, according to Fry. But the benefits go beyond a workout. The most astonishing 三生 0f laugehter?s power comes from a 1997 study of 48 heart-attack patients. 了Half Watehed cormedy ShowS for 30 minutes every day; the rest/? 5 “controls. After a year ten heart attacks, 了6_only two in the group that Watched the shows. ! Does a good laugh really help patients get well? Im a 7 _ experiment at the Uniyersity of California at Los Angeles, called Rx Laughter, sclentists plan to test 說 of ]aughter on children with serilous 過nesses, Including cancer Early fcesUIES Suggest fhat funny videos help kids handle uncomfortable or palnful procedures. Jistinge Ybarra。13, already knows that. He was in great pain when he woke up fiom surgery--z90 Bil Marx anda volunteer for Rx Laughter appeared at his bedside- Marx told jokes。 made faces and pranced around the hospital room. 」“Haying somethi ]augh 移站0 took my mind ofF the pain,”says Justin. 1“Wher ou can t help but feel better” B) at (C) landmark "” (D)until _(E)evidence (9) 有oWwy/ (HH) effect ,/" (Dof (J) compared wilth ga生了2本寺各乜千的 ers are learming Even the |

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