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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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英文 大學

哪一個段落沒有主題句？ 我覺得是第一個，對嗎？ 要怎麼替這個段落寫出主題句呢？

2 Despite different home cultures and countries, international students' main overall motivation is the desire get out on their own, to carve out a new direction in their lives. "Foreign students" do not casually abandon the comforts of family and cultural ties; they have done their homework on Canadian schools. All their preparation, though, cannot prepare them for the loneliness and ongoing difficul- ties they face, from cold winters to financial issues related to the higher tuition fees they must pay. Some students, though, emigrate to escape those same tight- knit families and bonds that others find so painful to leave behind. A Macleans "On Campus" report notes that family expectations may be opposed to students' visions for themselves and lead them to reject accepted values and career paths in their hometowns and countries. Csilla, a web-design student at Waterloo admits, "I was always supposed to enter my family's restaurant business in Budapest, but I felt suf- focated even working part-time as a server. Web design is my passion, and I wanted 12: CAUSE OR EFFECT [- a completely fresh start, something that is completely my own ("International Stu- dents"). Finding independent paths to their own dreams is the key here, whether students choose those paths as a result of personal ideals or as a reaction to pre-set future plans.
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商業與管理 大學

經濟學 請問有人可以教教我嗎ಥ_ಥ

7. In 2010, Americans smoked 315 billion cigarettes, or 15.75 billion packs of cigarettes. The average retail price (including taxes) was about $5.00 per pack. Statistical studies have shown that the price elasticity of demand is -0.4, and the price elasticity of supply is 0.5. a. Using this information, derive linear demand and supply curves for the cigarette market. b. In 1998, Americans smoked 23.5 billion packs cigarettes, and the retail price was about $2.00 per pack. The decline in cigarette consumption from 1998 to 2010 was due in part to greater public awareness of the health hazards from smoking, but was also due in part to the increase in price. Suppose that the entire decline was due to the increase in price. What could you deduce from that about the price elasticity of demand?
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生命科學與醫學 大學

（社區） 想詢問第38題的答案為什麼是C 橫斷研究法、世代研究法、病例對照研究 分別是什麼意思（這方面有點搞不清楚）謝謝！！

設而安的慢无次序時, 其中取重要的是:(A)對問題的了解(B) 解決問題的動機(C)問題的嚴重度(D)可利用的資源。 35. 由社區房屋的外觀來推判社區民眾的社經狀況,此種社區評估資料收集方法,屬於下列哪一種?(A)走街法(B)重要人物訪談 法 (C)參與式觀察法(D)社會指標。 36. 公衛護士發現融入社區,是進行社區評估的一大考驗,下列何種方法可以克服這項挑戰?(A)先了解誰是非官方的領導者, 並先與之接觸拜訪(B)請社區官方領導者,邀宴地方士紳(C)暫緩評估架構模式的選擇 (D) 參與社區的事件或活動。 D 37. 有關社區健康營造計畫之執行原則,下列何者錯誤?(A)以社區為主體(B)以賦權為方法 (C)以健康為主軸 (D)以政策為指 引。 038. 欲了解 SARS疫情爆發後,何種防護措施可以有效降低被感染的風險,下列何種研究設計最為適當?(A)橫斷研究法(B)世代 研究法(C)病例對照研究 (D) 隨機控制試驗 39. 有關對流行病的特性敘述,下列何者正確?(A)流行病並沒有特定的地理範圍(B)構成流行病的病人數目要達到一定的数量(C) 流行病是指急性傳染病(D)流行病的流行期間需要有 24 小時或24小時以上。 中 40. 華倫(Waren)學者提到社區有五種功能,某社區成立媽媽教室與導護媽媽等社團,乃行使社區那一種功能?(A)社會化(B) 社會控制(C)社會分配(D)社會參與。 41. 社區衛生護理人員幫助高血壓個案依據自己的健康需求擬定健康照護計畫,是應用下列哪一個策略?(A)衛生教育 (B)行為改

已解決 回答數: 1
英文 大學

B部分求解

A 同踢3Circle the correctWOIOCS y is doing Very well. 目ls shrinking) fast. (Fewer and fewer /了ore and mor (increasing / df are shopping or wat&hirt health awarenes5-一一 3 leatout more often these days as the-qsalty of food in many restaurants has, gotten worse). 4 Unhealthy food choices such as fast food are causing health problems_llke_obe ity to become (less common / jmmore widespread. B8 Complete the sentences-ee cribing trends. Use your own ideas. has decreased in the last few yes 1 The number of people who has improved over time. 2 3 4 These days, fewer and fewer people is/are becoming less common nowadays,. is/are getting richer. has become more widespread inthe lasttte!際 5 6 The problem Of C Work with a partner. Do you agree with your partner's statements in B? Why or why not?
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