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自然科學 大學

《普通化學》第九題跟第十題,感恩。

Alinie 2 PBurel H12 lapf Setul lagly x2 e determined by titfátinga 100 sample of KCror. Nos cag & beth 14 raqla 1: 191 +24100) No. (aq) + 2 Al Al EX Mn of laql4 2 1 7 Mn Oz (s) + Al(Orta 9. The blood alcohol (C2H5OH) level can be potassium dichromate solution, resulting in the production of Cr3+ (aq) and carbon dioxide. The reaction can of blood plasma with an acidic be monitored because the dichromate ion. (Cr20,?) is orange in solution, and the Cr" ion is green. The unbalanced redox equation is C₂H5OH(aq) + 3H₃0 (aq) + 2 CO2 (g) +12Hg) Me Cr2O,?- (aq) + CHșOH (aq) --Cr"(aq) + CO2(8) 14 Heag toe Cruon Lafla203149) If 31.05 mL of 0,0600_M potassium dichromate solution is required to titrate 30.0 g of blood plasma, Hamm Fapter (aq) determine the mass percent of alcohol in the blood. 0.143% Ca H5OH. 2- tize 32.0 g 10. An average human being has about 5.0 L of blood in his or her body. If an average person were to eat ht of sugar (sucrose, C12H22011, 342.30 g/mol), and all that sugar were dissolved into the bloodstream, how would the molarity of the blood sugar change? HO +1 HO +1 H &H to H - 31 OH HO HIP 126 0 HO +1 + 5e OH OH OH (+36 ) x2 t6 Cr2O7 - 20+ 3+

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自然科學 大學

請教一下,我今天做到一個實驗是酸鹼滴定實驗,但我忘了圖上要的酸度與鹼度的定義是甚麼?我覺得我的數據有點奇怪,正常來說,算%會到124%嗎?

万粉 度(%) 酚酞指示劑 滴 ·食醋的酸度測定 1009.49 . 5 b 6 soo 1. 1ooo CH 0.0012 x16Q、 0,12%. 1008 -x100 CH3COOH 1000 X 100 CH3COOH(ml) 20 0.6 the = 12 % 氫氧化鈉(NaOH) 食醋 甲基橙 實驗步驟 to = 4 1000 40.9 too 29 取一乾淨5ml 刻度吸量管,精確吸取 5ml 的食醋於250ml 錐形瓶內,加入約100ml 的純水,使 49 起充分溶解,再加5滴酚酞指示劑(溶液為無色)。 已知濃度 0.1N 的NaOH 的標準溶液滴定至溶液成粉紅色為止。 3. 假設食醋的比重是1.00,依下式計算食醋的酸度: 0-1 x Nox NbxV 酸度(%)= 3 4. 重複實驗一次,求出食醋中的酸度平均值(%) - 二、去污粉鹼度測定 1. 稱取約0.25g的家庭用去污粉倒入250ml 錐形瓶內,加入約100ml 的溫水,使起充分溶解,冷 卻後再滴5滴甲基橙。 vol 2. 已知濃度 0.1N 的 HC1 的標準溶液滴定至溶液成橙色為止。 (600 3. 依下式計算去污粉的酸度(Na2O計): 36.5 NaxVa> 鹼度(%)-- X 100 [00 3.65 x2 Na2O(g) 4. 重複實驗一次,求出去污粉中的鹼度平均值(%) 200 7.30 slxy F1 249)) 62 3lio.25 NX Too x Toro | Na20 2000 32 al XIX 29 Xyup.

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自然科學 大學

求解 為什麼動量不需要代速度值?🤔

6.51 Using Heisenberg's uncertainty principle, calculate the uncer- tainty in the position of (a) a 1.50-mg mosquito moving at a speed of 1.40 m/s if the speed is known to within £0.01 m/s; (b) a proton moving at a speed of (5.00 + 0.01) X 104 m/s. (The mass of a proton is given in the table of fundamental constants in the inside cover of the text.) (a) Ax >= h bar /24p = 6.626*10-34/(1.5*10-6*0.01)/41 = 4/41*10-27 m (b) Ax >= h bar/24p = 6.626*10-34/(1.67*10-27*0.01)/41 = 3/41*10-10 m *

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自然科學 大學

請問這題怎麼解😢😢

--- B - a thin uniform rod (mass 3.9 kg, length 3.9 m) rotates freely about a horizontal axis A that is perpendicular to the rod and passes through a point at a distance d= 1.0 m from the end of the rod. The kinetic energy of the rod as it passes through the vertical position is 20 J. (a) What is the rotational inertia of the rod about axis A? (b) What is the (linear) speed of the end B of the rod as the rod passes through the vertical position? (c) At what angle o will the rod momentarily stop in its upward swing?

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自然科學 大學

生物~植物部分 想請問A.B是錯在哪~感恩!

> > 我。 84.下列有關維管束植物根部發育與構造的敘述,何者錯誤? A. 維管束植物成熟時,均具有直接由胚根(radile)發育而形成的根系構造 B. 軸根系的雙子葉植物與鬚根系的單子葉植物,其根部都會形成支 C. 位於植物的莖部與莱部形成的不定根,有可能再形成支根 D. 支根大都形成於較成熟之根毛區, 藉此與主根的維管束得以連結 E. 當維管束植物氮源缺乏時,根部即與真菌共生形成菌根,或與細菌共生 成根瘤 > Kte

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自然科學 大學

水文學——降水與損失 如圖,請問有人知道這兩題該怎麼算嗎? 翻遍教科書教過的內容根本沒想法⋯

> 0 2-14 有一矩形集水區,其四個角落的座標分別為(0,0),(0,10), (14,10) 和 (14,0)。集水區內設有四個雨雨量測站,各測站所在位置的座標及降雨量如下 表。所有座標值的單位均為公里。試以徐昇氏法推算此集水區的平均降雨量 及逕流總體積(註:假設無任何降雨損失) o 雨量站位更 (4,2) (4,7) (11 , 7) | (11,2) 降雨量(cm) 1.5 2.0 2.4 4.3 ( 86 水利工程簡任升等)

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自然科學 大學

求詳解 謝謝🙏

m m R 15. A small particle of mass S mis pulled to the top of a frictionless half-cylinder (of radius R) by a light cord that passes over the top of the cylinder as illus- trated in Figure P7.15. (a) Assuming the particle moves at a constant speed, Figure P7.15 show that F= mg cos 0. Note: If the particle moves at constant speed, the component of its acceleration tangent to the cyl- inder must be zero at all times. (b) By directly integrating W= F dř, find the work done in moving the particle at constant speed from the bottom to the top of the half-cylinder. =

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自然科學 大學

光學第3題(2.38)請問如何解選項c🙏

3.00 85 09:49 ul. RES Optics Homework 1...748220677e2a.pdf ka KI : 。 Optics Homework 1 1. 2.2* Show that the function $(y, t) = (y – 40) is a solution of the differential wave equation. In what direction does it travel? 2. 2.6 How many wavelengths of a green laser (1 = 532 nm) can fit into a distance equal to the thickness of a human hair (100 um)? How far will the same number of waves extend if they originate from a micro- wave oven (v = 2.45 GHz)? 3. 2.38 Which of the following expressions correspond to traveling waves? For each of those, what is the speed of the wave? The quanti- ties a, b, and c are positive constants. (a) (z, t) = (az – bt)? (b) y(x, t) = (ax + bt + c)2 (c) 4(x, t) = 1/(ar? + b) 4. 2.43 Write an expression for the wave shown in Fig. P.2.43. Find its wavelength, velocity, frequency, and period, Figure P.2.43 A harmonic wave. I=0 40 100 300 500 -20 401 -60 0.66 X 10-15 (nm) 100 300 500 I = 1.33 X 10-15 (nm) o 二

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