看不懂老師的算式 有人能幫我拆解步驟解釋一下嗎 或是另外寫易懂的算式過程 拜偷

A sample containing 25.14g of neutral salts, glucose and a sodium carbonate/bicarbonate buffer was dissolved in 100 ml of water. A 25 ml aliquot of the resultant solution required 20.35 ml of 0.0987 M HCl when titrated to the PP end-point. A second 25 ml aliquot was titrated to the MO end-point and required 56.75 ml of the acid. Calculate the percentage of Na2CO3 (molecular weight 106) and NaHCO3 (molecular weight 84) in the sample. 含有25.14克中性鹽、葡萄糖和碳酸鈉/碳酸氫鈉的樣品將緩衝液溶解在100ml水中。需要25毫升等份所得溶液滴定至PP終點 時,使用20.35ml 0.0987 M HCl。第二份25毫升等分樣本是滴定至MO終點,需要56.75ml酸。計算百分比樣品中的Na2C03 (分子量106)和NaHCO3(分子量84) 39

求問這題的c小題

4. A solid mixture of Na2SO4 and K2SO4. A 0.205 g of sample of the mixture is dissolved in water. A excess of an aqueous solution of BaC12 is added. The BaSO4 is formed is 0.289 g. a. What mass of SO4-2 ion is in the sample? b. What is the mass percent of SO4-2 ion in the sample? c. What are the percent compositions by mass of Na2SO4 and K2SO4 the sample? a. 0.123 g of SO4-2 ion b. 60% of SO4-2 ion c. the mixture is 61% K2SO4 and 39% Na2SO4

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

有人知道圈起來的地方的意思是 AgI質量乘 142/233＝新生成的AgCl質量嗎？ 所以這一串式子是原本的AgCl質量再加上後面進行反應新生成的AgCl質量嗎？

4-17. A 0.6407-g sample containing chloride and io- dide ions gave a silver halide precipitate weigh- ing 0.4430 g. This precipitate was then strongly heated in a stream of Cl2 gas to convert the Agi to AgCl; on completion of this treatment, the precipitate weighed 0.3181 g. Calculate the per- centage of chloride and iodide in the sample.

《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+

EDTA滴定，求解🙏

2. Titration of Ca2+ and Mg2+ in a 50.00-ml sample of hard water required 23.65 mL of 0.01205 M EDTA (C10H16N203). Calculate the hardness of the water sample, expressed as ppm CaCO3 Element Ca Mg C H N o Atomic Mass (g/mol) 40.08| 24.31|12.01|1.008| 14.01|16.00

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)。

大一普化5.50求解

3.43 AN 失 交 (方 N 全 只 憲 5.49 5,@ Re Problems 5 0t ln the stratosphere itadiation from the sun. and presSsure of ozone in Ths absSQTt Typieal the Stratosi Kandl0人10 am re spectively. How many ozone molecules are present in ]l.OL ofair under these conditions? Assuming that air contalns 78 percent N2, 21 pereemt O>, and 1 percent Ar, all by volume, how many mol- ecules of each type of gas are presentin 1.0Lotair 肚STP? A 2.10-L vessel contains 4.65 g ofa gas at 1.00 atm and 27.0。C. (a) Calculate the density of the gas In grams perliter. (b) What is the molar mass of the gas。 Calculate the density of hydrogen bromide (HBr) gas in grams per liter at 733 mmHg and 467C. A _ certain anesthetic contains 64.9 percent Co, 13.5 percent H, and 21.6 percent QO by masS. At 1205C and 750 mmHg, 1.00 L of the gaseous com- pound weighs 2.30 g. What is the molecular formula 9f 人he compound? Aecompound has the empirical formula SF4. At 20.0 0.100 g of the gaseous compound oceuplesa Volume of22.1 mL and exerts apresSure of 1.02 atm, What 1S its molecular formula? Dissolving 3.00 g of an impure Sample 0f calcium carbonate in hydrochloric acid produced 0.656L 人 carbon dioxide (measured at20.0C and 792 mmHg). Calculate the percent by mass of caleium carbonate in the sample. State any assumptilons, oleulafe the 和ass in orams Ofhydrogen chloride bro-

大一普化 5.36求解

5.38 9389 信4 5,42 sphere (about 30 Where the temperatu lbove the surface of Earth), >and presSure are 一235C : h gd 交 and 3.00 XX 10 atm, respectively. Calculate the final Volume of the balloon. The temperature ot 2.5 L of a gas initially at SUN increased to 2507”C at constant volume. Calculate the final pressure of the gas in atm. The pressure of 6.0 L of an ideal gas in aflexible contalner 1S decreased to one-third of its original presSure, and 1ts absolute temperature 1s decreased by one-half. What 1s the flnal volume of the gas? A gas evolved during the tfermentation of glucose (wine making) has a volume of 0.78 L when mea- sured at 20.1?C and 1.00 atm. What was the volume of this gas at the fermentation temperature of 36.5 C and 1.00 atm presSure? An ideal gas originally at 0.85 atm and 66”C was allowed to expand until its final Volume, preSSure, and temperature were 94 mL, 0.60 atm, and 45 C, respectively. What was its initial volume? The volume of a gas at STP is 488 mL. Calculate 1ts volume at 22.5 atm and 1507C. A gas at 772 mmHg and 35.0”C Qceuples a Volume of 6.85工. Calculate its volume at STEP. Dry ice is solid carbon dioxide. A 0.050-g sample ot dry ice js placed in an evacuated 4.6-L vessel at 30。C. Caleulate the pressure inside the VesSel after all the dry ice has been conVerted to CO gasS, Avolume of 0.280Lofagas at STP weighs 0.400 g. Calculate the molar mass Of the gas. Aquantity of gas Weighing 7.10g at741tor and 445C oeeupies a volume of 5.40L. What is its molar mass? Si人2 5.93 5.54 Dalt 和Ae0U76 5 5.56

為什麼答案是d 🙏🙏🙏

Which of fhe following would NOT be considered an 旋fe7s/ve p/ope/fy describing an unknown sample? at is asolid at 25”C. bp)蔬has a density of 1.38 g/cm3. C)t melts at 62.0” C. djt has a volume of 0.52 cm3. e湃jS shiny.