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.

想請問這題的醚和胺的沸點可以如何排序？ 因為我印象中氫鍵的影響比極性大，因此不了解為什麼胺的沸點比醚小 謝謝🙏

56. List the following compounds from highest boiling to lowest boiling: NH₂ 分子量 - * b₁p= HB dipole 為何 ↓ relatively weak HB OH ⑥ dipole-dipole interactions Q= LOH has two groups that hydrop bund ~HNY WH HB的影響力不是通常大於極性嗎? OH Obme electronegative thun N, OH Ingen bond are stomper than NH₂ primary amines form stronger hydrogen bond than seculary relatively weak no bydrogen had hydrogen bonds HB→分子量(分散戶 nly dipic dipole →接觸面積→極性 hah no hydrogen bon weaker dipole-dipole interactions tha oxygen-containing compounds because N is low electro negative than O

請問Mass光譜切割到最後 剩下的基團怎麼寫？ 切下乙烯、C=O後 剩下的基團要怎麼標示？ 分子量剩下55，是C3H5N 這是什麼基團或是結構嗎？

Relative Intensity 100 80 40 MS2008-03710CW 0 mm 83 20間距相差55m/Hz,可知可能為 111m/z出現訊號,可推 測分子量可能為111 111 間距相差28m/Hz,可知可能為-CH=CH(乙烯基) 55間距相差28m/Hz,可知可能為C-0 50 v/tbn/pyntyy.................... 100 150 m/z 200 250 28 28 55 NH2

想問3-9的a跟c

Problems 3-1. Explain the difference between *(a) random and systematic error. (b) constant and proportional error. *(c) absolute and relative error. (d) mean and median. *3-2. Suggest two sources of systematic error and two sources of random error in measuring the length of a 3-m table with a 1-m metal rule. 3-3. Name three types of systematic errors. *3-4. Describe at least three systematic errors that might occur while weighing a solid on an analytical balance. *3-5. Describe at least three ways in which a systematic error might occur while using a pipet to transfer a known volume of liquid. 3-6. Describe how systematic method errors may be detected. *3-7. What kind of systematic errors are detected by varying the sample size? 3-8. A method of analysis yields masses of gold that are low by 0.4 mg. Calculate the percent relative error caused by this result if the mass of gold in the sample is (a) 500 mg. (b) 250 mg. V(c) 125 mg. (d) 60 mg. 3-9. The method described in Problem 3-8 is to be used for the analysis of ores that assay about 1.2% gold. What minimum sample mass should be taken if the relative érror resulting from a 0.4-mg loss is not to exceed *(a) -0.1%? (b) -0.4%? (c) -0.8%? (d) - 1.1%? 3-10. The color change of a chemical indicator requires an overtitration of 0.03 mL. Calculate the error if the total volume of titrant is percent relative (a) 50.00 mL. (c) 25.0 mL. 3-11. A loss of 0.4 mg of Zn occurs in the course of an percent relative analysis for that element. Calculate the error due to this loss if the mass of Zn in the sample is *(b) 10.0 mL. (d) 30.0 mL. 190 (c) 188 (d) 4.52 x 103 4.63 x 103 4.53 x 10 ³ √6 *(a) 30 mg. (b) 100 mg. *(c) 300 mg. (d) 500 mg. 3-12. Find the mean and median of each of the following sets of data. Determine the deviation from the mean for each data point within the sets, and find the mean devi- Vation for each set. Use a spreadsheet if it is convenient. *(a) 0.0110 0.0105 (b) 24.53 0.0104 24.68 24.81 24.77 39.61 862 (f) 850 MA 3-13. Challenge Problem: Richards and W the molar mass of lithium and colle data. 24.73 Experiment 1 2 3 4 5 6 194 447 X 10 7 448 X 107 4.58 X 10 (a) Find the mean molar t workers. (b) Find the median molar ma (c) Assuming that the cam molar mass of lithium is the absolute ertor and of the mean value demi Willard. (d) Find in the chemical ues for the molar mus since 1910, and ag a table or spreadshera 1817 given in the a Richards and Willd. Com mass versus year to la of lithium has chang Suggest possible abruptly about 18 ant de (e) The incredibly deals Richards and W that major changes will occur. Disc calculation in pat (f) What factors ha since 1910? (g) How would you mass? 6See Chapter 2 of Applications of Microsoft Excel in Analytical Chemistry, 4th ed., for information about statistical 7T. W. Richards and H. H. Willard, J. Am. Chem. Soc., 1910, 32, 4, DOI: 10.1021/ja01919a002. built-in statistical functions. "Answers are provided at the end of the book for questions and problems marked with an asterisk The I of ₂ or inc rce of able vas error c often in individu ate resul data in rtainties. dimensio andom e analysts The result

求解答案是否正確

Multiple-choice questions: (70 points) write the letter of statement that is not true: 1. A.B.U The Drude Model: (a) It is a classical approach using concepts from the kinetic theory of gases. (b) A relaxation-time approximation is used where the probability of collision is l/t. (c) No forces act on the electrons in between collisions. (d) It predicts accurately the electronic heat capacity of metals. 2. The Sommerfeld Model: (a) The crystal potential is replaced by an average Coulomb potential. (b) The separation of states is so close that a continuum model can be applied. (c) The electrons are highly localized due to a strong crystal potential. (Q) The energy of the highest occupied state at 0 K is the Fermi energy. 3. Density of states in k-space, N(k): (a) N(k) is determined by the boundary value conditions. (b) For lattices in any dimensions, N(k) is constant in k-space. (C) N(k) depends on the direction and magnitude of k. (d) It is directly proportional to the volume of the crystal. E影響, c 4. The Fermi surface of a metal: (a) is responsible for many of the transport properties of the metal, (b) depends on the nature of the chemical bonds, (c) is always a sphere, (d) can involve mixing of electron orbitals. ✓ 5. The conductivity of a material () increases with the mobility of its carriers, (b) increases with the density of carriers, (C) it is inversely proportional to the energy gap. cogu changes with temperature. 6. BID Plasmons: (a) They are an important characteristic of the Sommerfeld electron gas model. (b) Plasmons occur spontaneously in metals. (c) They are related to charge density oscillations. (d) The Plasmon energy is typically of the order of 10 eV. The Fermi energy Ef in intrinsic semiconductors 8) is usually close to y E, at OK (b) it ACiD. can increase or decrease with temperature depending on the ratio of hole and electron effective masses, (c) it represents the point at which the probability of occupation is 12, even though there may not been any states with that energy, (d) its value relative to the electronic bands must remain unaffected in the presence of defects or interfaces.

請問第七題怎麼解

60 s, turn 90 20 km/h for 2.0 min, turn 90° to the point, (a) how far are you from your starting point, and what direction relative to your initial direction of travel are you? V During volcanic eruptions, chunks of solid rock can be blasted out of the volcano; these projectiles are called volcanic bombs. Figure 4-22 shows a cross section of Mt. Fuji, in Japan. (a) At what initial speed would a bomb have to be ejected, at angle 0o = 60.0° to the horizontal, from the vent at A in order to fall at the foot of the volcano at B, at vertical distance h = 2.60 km and horizontal distance d = 9.40 km? Ignore, for the moment, the effects of air on the bomb's travel. (b) What would be the time of flight? (c) Would the effect of the air increase or decrease your answer in (a)?onatlar slow orl w moito Movisio Olovo vibolov te tootsodio dos olvistatani se moltotib nur no vodo as vd botu 29 vd baidot otsi Nomstl moll bottom 12 A plane flies 5 then 1100 km sout) trip, what are the displacement, the velocity, and (e) is 13 An astronau of 4.5 m. (a) Wha eration has a ma minute are requ period of the m 14 A basebal mum height al after reaching that is 86.0 m (a) What may ball? (b) How the ball strike blitt 00 Troede Vibolov sister sam 12 d B 15 The ran also on the place to plac broad jump (where g= by how mu instead in 1 Figure 4-22 Problem 7. 8 Oasis A is 90 km due west of oasis B. A desert camel leaves A and takes 55 h to walk 75 km at 37° north of due east. Next it takes 45 h to walk 65 km due south. Then it rests for 5.0 h. What are the (G) magnitu Cia

想問5-9 該怎麼算 ？ 第一個選項就可以了 謝謝

the sample size? (b) 250 ing? 211% -6208 *(a) 500 mg. *(c) 150 mg. Xloo to 10.4 ) X100% =0108 / mg 506 016 5-8. A method of analysis yields masses of gold that are low A by 0.4 mg. Calculate the percent relative error caused ylvila by this result if the mass of gold in the sample is 625 mg.6 20 (d) 70 (c) Dit X 106% 8.6 5-9. The method described in Problem 5-8 is to be used for the analysis of ores that assay about 1.2% gold. What minimum sample mass should be taken if the relatived) error resulting from a 0.4-mg loss is not to exceed *(a) -0.1%? (b) -0.4%? 5 * (c) -0.8%? (d) - 1.1%? Slastin 0 (14)。

一直算都錯😖，求解

Problem: relative to 丸 Is om always smaller than zz, larger than we orthe same Ph as uu, or does it have sorme other shed k 中 Telationship? COTn- TeaS,。 (4 Lisa rushes down onto a subway 7? 1the Platform to find her train already 主 leparting. She stops and watches b the cars go by. Fach car is 8.60 m ( 語 long. The first moves past her in 站 1.50 sand the second in 1.10 5. 實 Find the constant acceleratlion Of 時 則 thetralin. With )eSlt CHALLENGE PROBLEMS np lt hes is 42. Two thin rods are fastened to ~e on the inside of a cCircular TIng as shown in Figure P2.42. One rod of length Dis vertical, and 17th the other of lenoth 了 makes an

求圈起來的幾題

補史名www asftrppfysfts 600) For Thoughtand Diseussion tneuish the Aristotelian and Galilean/Newtonian views ofihe ball bounees ofrawall with the same speedithad beforeithit Wall Has its momentum changed? Hasaforoe acted on the 2 Has aforee acted on the wall? Relate your answers to New aws of motion ten use the term "inertias to deseribe human sluggishness 5this usage related to the meaning ofFsinertiae in physics? does aceiling fan continue to rotate even after you have vitched it ofP? Wek erashes into a Stalled cear A student trying to explain the es ofthis event claims thar no forees are involved: the car Tin the way”so itgot hit Commen foot astronaut kicks a ball, hard, across aspace station balls apparent weightlessness mean he astronauts toes 下avity on Jupiters moon Io is one-fifth that on Would happen te your weight and to your mass if nIo? tis the direcetion of momentum oFamoving body? Does it Fthe body: plane aceelerates down the munway, you take your keys r poeket and suspend them by a thread. Do they hang force from the chairon you. iir? Hnot, what forees are fxerrisesaned Problems 85 $ 還2620Groeoeoeardaoeos WiA poaor Wonoeno0 Op ir oa 20。 Staring frorm rest and undergoing constan acceleratiom,a920-kg ar covers 410 min $.15 8. Find the foree on the car 21 dropping dontest, a student encatses am 83-g cgg in large Styrofoam block. fs g emn'texceed 2.0N and 計the bloek hits the g pow mueh must the Styror jompress on impaet) Note: The aceelei assoeialed with stOppi gravity while the Styrofe the ground. 22. Inatront-end collision, a 1400-kg car with shockzabsorbing bump: ems can withstand amaximum force of 75kN before damage Gccurs: Hthe maximum speed foranondamaging collision is 9.0 kmzh, by Bow much must he bumper be able to move relative to the car? section 4.4 The Force ofGravity 23。 Show that the units of aceeleration can be written as N/kg- Why doesitmake sense to give gas 9.8 N/kg when talking about imass and weight? 24. Your spaceship crashes on one of the Sun's planets, Fortunately 上 the ship's scales are intact and show that your weightis 680 N.H your mass is 58 kg, where are you? (imr: Consult AppendixEE) Your friend can barely lift a 35-kg concrete block on E: massive ablock could she lift on the Moon? 26 Acereal box says "net weight 350 grams” Whats the actual Weight ta in SLunits and (b) in ounees? 27. Youre asafety engineerforabridge spanning the U,S-Canadian border. U.S. speeifications permit a maximum load of 10 tons What load iimit should you speeify on the Canadian side. where welght is given in kilograms? 28.。 The gravitational acceleration atthe lntermational Space Stations altitude is about 91凶 oFits surface value. Whats the weightofa 64-kg astronaut atthis altitude? ection 4.5 Using Newton's SecondLaw A 50-kg parachutist deseends atasteady 40 km/h. What foree does air exert on the parachute? 30, A 960-kg motorboat accelerates away from adock at2.1 m/s Its propellerprovides a3.9-kN thrust force. What drag force does the water exert on the boat? An elevator aceelerates downward at2.4 ms. What force does the elevator's floor exertona52-kg passengery 32. At 560 metric tons, the Airbus A-380 is the World's largest air- liner Whats the upward force on an A-380 when the plane is (am flying at constant altitude and (b) aceelerating upward at 15m/s2? 33. Yourre an engineer working on Ares 1 NASAs replacement tor the space Shuttles. Performance speces call for afirst-stage TOcket Gapable ofaccelerating atotal mass 0f 600 Me vertically ftom Testt0 7700 km in 1.7 min. Youre asked to determine tbe re- quired engine thrust (force) and the foree exerted ona79-kg as- tronaut during Tiftoff. What do you Teport? 34. You step into an elevatorand itacceleratesto adownward speed gfF8.8 mAS in 2.4 5 Quantitatively compare your apparent weight during thistime with youracetual weight, 44.6 NewtonsThirdLaw ional foree does 3 5600-kg elephant exer 必 63. she jumps ofta140-emhi過台 人 rdheras she falls?