Question

I need help with this experiment please....

CHE 105 LAB MANUAL Lab 10 Report Name: 2. The chemical equation for our specific buffer system was deliberately not given in the discussion. What is the chemical equation for our buffer system? 3. The Henderson-Hasselbach equation given in the discussion had cuacau In this prelab and report, we want ICH,COOH) Want [CH,COO-Write the equation from the discussion below and then convert it to have 'CHCOOH). ICH,COD-1 in it. 4. Now, time to determine how to prepare your buffer. 2. What will be the pH of the buffer that you will prepare today? There is no wrong answer, but choose a pH between 4.0 and 5.5 to make the lab easier to complete. 9 THAT 4.90=4.74 +09 [CH₂027 LH3CO2HS b. Use the Henderson-Hasselbach equation to find the coulenne needed to prepare a buffer with the pH you selected in part a. Remember that the K of acetic acid is 1.82x10. PH = -log (Kaltlog [14 ] 20.16-109 [CH3C027 [HECHT 4.90-19(182X10 + CH3C027 0.16 log (CHICO CH3CO2H /10 = 10°C Hico, 17 1:44 - [CH2.001] [CH3CO2H] c. How many mL of 0.50 M CH,COOH will you use to make the buffer with the pH selected in part b? There is no wrong answer, but chose a value between 20 mL and 40 mL to make the lab easier to complete. - 20 ml d. How many moles of CH,COOH will you be adding to the buffer system based on your answer to part c? -0. Somol CH3COH 20mtsoth.. ToomL soth = 1 [CH3CCH] = 0.01 mol CH3 CO2H Prelab gwestions continue on the next page! 140

Answer 1

. 2. Chemical Equation relating the buffer System is as follows. си, слън (4) = cң сого" () + *(44), («. = 1.8 2x/s". " ев, СИ у weakaid from CH₂ COONa cenjugete base of weak acid L acidic Buffer Ка - Сн*) Со сл°] ces westen lopka + log (c, care a lights -lука - 14 ) . -1711) 1 pH opka - log, cene 7 ) К (C up А) 4, les no. of moles of all cool = 0.0/mole ( calculated con O in Part (d)) - so, concentration of eH cooh/ Ceng Cook] in 250 ml Buffer. "", . от н. Тоо»

(f) lling the relation denined in part (h) in ie. [ubwoof Гү сън) -2 1.44 cescudo) - CUI COOH ] X1.44 [usccom] 20.0481,447 = 0.0576M (9) no. of moles of Ch Crona = 0.0576 * 254 - . Choo 0.0144 moles toso ceps cues) > [couNa ] 0.0576m ch) Grans of cq anna that must be added to the buffer a no. of moles of CH Conax Molar mas 000144 x (84+3+32 7??) of cu corona nowe it. Then fill the distilled water in = 1.1819 Procedure. - Take a beaker and rinse it. Then fill the distilled - it upto the mark of 250 ml. li) weigh 24 g of cl woh and add it in the above arome bea (We get 0:04M CM OH eencentration), (iii) then weigh 1.1819 of Cheona and add it in the Ivo A buffer solution anturning faol 4 CH, Lowo na û brehared 0:04M 30.0576M Sacidic buffer. dadd it in the above solution.