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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Laser welding is a technique in which a tightly focused laser beam is used to deposit enough energy to weld metal parts together. Because the entire process can be automated, it is commonly used in many large-scale industries, including the manufacture of automobiles. In order to achieve the desired weld quality, a particular pair of steel parts being joined must absorb energy at a rate of about 1.1 x 104 W/mm². A common laser welding system employs a Nd:YAG laser operating at a wavelength of 1.064 µm. At this wavelength, this particular set of steel parts will absorb about 80.% of the incident photons. If the laser beam is focused to illuminate a circular spot with a diameter of 0.020 in, what is the minimum power (in watts) that the laser must emit to reach the 1.1 × 104 W/mm² threshold? (Recall that 1 W = 1 J/s.) W How many photons per second does this correspond to? (For simplicity, assume that the energy from the laser does not penetrate into the metal to any significant depth.) Submit Answer Try Another Version 1 item attempt remaining

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When a helium atom absorbs light at 51.31 nm, an electron is promoted from the 1s orbital to a 6d orbital. Given that the ionization energy of (ground state) helium is 2372 kJ/mol, find the longest wavelength (in nm) of light that could eject an electron from the excited state helium atom. nm Submit Answer Try Another Version 2 item attempts remaining

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The photoelectric effect can be used to measure the value of Planck's constant. NOTE: The following data are fictional, and will give a result that is quite different from the real value of Planck's constant. Be sure that you do not use the real value of Planck's constant in any calculations here. 1 S -1 Suppose that a photoelectric effect experiment was carried out using light with v = 7.56 × 10¹4 s-¹, and ejected electrons were detected with a kinetic energy of 2.41 × 10-¹1 J. The experiment was then repeated using light with = 9.81 × 10¹4 s and the same metal target, and electrons were ejected with a kinetic energy of 9.09 × 10-¹1 J. Use these data to find a value for Planck's constant (in J • s). Hint. It may help to start by thinking about how you would calculate the metal's binding energy if you already knew Planck's constant. Submit Answer S Try Another Version 2 item attempts remaining

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Chrome 檔案 M Gmail 3 My Courses Course Home Syllabus Scores YouTube Pearson eText Study Area Purchase Options User Settings Course Home X Ghe binding energy of a two-par x + openvellum.ecollege.com/course.html?courseld=17667848&OpenVellumHMAC-9c8d5dd7baa0c70ec3a75db4e52f2d39#10001 Document Sharing Course Tools 單 檢視 歷史記錄 書籤 設定檔 分頁 視窗 說明 地圖 > 翻譯 <L.8 Problem 8.51 Part A W = Submit VAE Provide Feedback How much work would be required to move a satellite of mass m from a circular orbit of radius r₁= 2re about the Earth to another circular orbit of radius r2 = 3rE? (rE is the radius of the Earth.) Express your answer in terms of the variable m and constants rE, ME, and G. Request Answer https://session.masteringphysics.com/myct/itemView?assignment ProblemID=176946298 10月 13 tv ? 10月13日 週四 上午12:37 - 999+ ■ 8 of 10 更新: Constants Next >

求證明(b)的過程😭感謝~

(I) A soccer player kicks a ball at 15 m/s at 20° above the horizontal to another member of the team. At what speed should the second player run in order to reach the ball just as it lands? The initial separation of the players is 25 m. he (II) A basketball player throws the ball with initial velocity vo at above the horizontal to the hoop which is located a horizontal distance L and at a height h above the point of release, as shown in Fig. 4.44. (a) Show that the initial the speed required is given by an vſ gL 2 cosO(tan 9 - h/L) (b) Show that the angle a to the horizontal at which it reaches the hoop is given by tan a = 2h/L - tan 0. = Vo h L FIGURE 4.44 Problem 16

力學 救救我 謝謝！（第三題不用）

1. Considerathin rod ofuniform linear mass density pL with mass 4/ and length /, find the gravitational potential。dp/有)。at a perpendicular distance Afrom the center ofthe rod. You may find the integral in (E.6) in Appendix E useful 2. A spherical planet of radius 人> consists ofacore of radius 有/ with uniform density pi. and a thick outer cloud of dust with umiform density p: Find the force (magnitude and direction) onamass箇inside the dust cloud ata position ARp from the planetcenter( 吃<訪<記), 3. Use Fermat's principle by applying calculus of variation to minimize the time oflight passing from medium ofrefractive index jg, to another medium ofrefractive index >, derive the Snells law ofrefraction: js光 名2s 銷 4. Consider the Atwood machine oftwo masses connected by amassless string oflength 7overapulley ofradius gas shown, (a) Write down the total kinetic energy and potential energy in terms of the coordinatex Hence obtain the Lagrangian ofthe system. (b) Derive the Lagrange's equation of motion and hence find the acceleration ofthe masses. x 和二 工

求解圖裡UICK quiz的第二小題

acit0r 1taneOuls CUrTent Differentiating Equation 27.22 with respectto time gives the inst: as afunction of time: 4 tt號 一Fe ptasafurc 主二 where Q;/有CC 三方 is the initial current. Figure 27.15b 5 in the resistor that we guessedin order to-apply Kirch Equations 27.15 and 27.21. Equation 27.23 shows that the ci ing capacitor is negative, indicating that the current 1s Figure 27.15c. Both the charge on the capacitor and the ct tially at a rate characterized by the time'constant7了三用C. 人 i 一 GOuicK ouiz 27.5 Considerthe circuitin Figure 27.17 and assume the battery has after the switch is closed, what is the currentin the Figure 27.17 no internal resistance. () 」 battery (a) 0 (b) &/2A(G 28/Z04 8/元(e) impossible to determine (ii) After a 有 eyerylong time, what is the Currentin the battery? Choose from the same choices. theswitch is CC (3 前:銜1加信介2放 IntermittentWindshield Wipers nobiles are equipped with windshield wipers that can operate intermittently during alight rainfall. How does ofsuch wipers depend on the charging and discharging ofacapacitor7 民 The wipers are part ofan 及C circuit whose time constant can be varied by selecting different values of及through amultipo- Sition sWitch. As the voltage across the capacitor increases, the capacitor reaches a point at which it discharges and Higgers the wipers. The circuit then begins another charging cycle. The time interval between the individual sweeps of the wiperS 1 determinedjby the value ofthe time constant.

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te theSe_ VaIUGS. Whlich wave has the elocity? What type Of electrormagnetlc fad1iatlon does each wave TepreSent 2, One type 9t electromagnetic Tadiatlon has a fredquency 0 107.1 MHz, another type has a: velength of 2.12X 10 “m, and another type of electroinagnetic Tadiation has photons With energy equalto 3.97 X 10 19 J/photon. Identity each type gf electrormagnetic radiatlon and place them m order 0t increasing photon energy and increasing fteduency. energy at a Wavelength of 150. nm. The total mitted by acarbon sample is 1.28 人 10

第二題麻煩一下~謝謝

ae OLIE_UDOO, Look up the density ofa typlical surface rock like granite in anothersourceand compareitwith the density ofthe Earth. 2 入 which is the nu人所 Ofa 由 Can be modeled as a sphere with a diameter of 2.4 fmtand a mass of 1.07 X 10 ?7 kg. (a) Determine the density of the proton. (bp) State how your answer to part (a) compares with the density of osmium, given in Table 14.1 in Chapter 14. ?, Two spheres are cut from a certain uniform rock. One has TadIus 4.50 cm. The mass of the otheris five times greater. Find its radius. 4 What mass ofa material with density p is required to make 全 時 同 划 呈