Question

4. Calculate the pH of your sarhple at several points during the titration. In each case, record your calculated pH and your experimentally observed pH. Calculate the initial pH of your sample before any titrant was added. (Do not forget that you added some DI water to your sample before you began titrating.) Record your calculated pH value below and the experimentally observed value from your graph. a. Observed: Calculated: b. Calculate the pH after 7.00 mL of NaOH was added. Record your calculated pH value below and the experimentally observed value from your graph. ObservedCalo Calculate the pH at 1.00 mL of NaOH added prior to the equivalence point. Record your calculated pH value below and the experimentally observed value from your graph Calculated: c. Observed: Calculated:_ d. Calculate the predicted pH at the measured Veq. Record your calculated pH value below and the experimentally observed value from your graph. ObservedCalculated: Calculate the pH at 7.00 mL of NaOH added after the Veq. Record your calculated pH value below and the experimentally observed value from your graph. e. Calculated: Observed: HCG 1032m -Caleulated-V Initial H,0-4. qSL一一Final Hot168 nt. 25.00mL HCI vol used Total vol Bruret otal volpH NaOH added pH color Bruret Reading NaOH addedpl 15.01 14.5し12.411 Yellow color ReadingO 0.49m 000 L33 Ple Yel 15.05 4.56 4.62 47 Yelle .6 61.4 15,40 14. 2.64 Yeilo .52 5.5115 22.73 Yetlo | 15.66 1115.55 Ipinっ |10:06 |lien o.06 (o , 55 ellon llow Bruret color Total vol Total voll pH Bruret color Reading NaOH added NaOH added Reading 15. g 5.q3 15.44 3.3 vel 7.85 7.34 1.3 5.48 5.44 363 4.30 pnk o.72 20.23 1.6 6104 15.60 (6.2 5.72 4 lo Rrt 6:3115.82 51 6.34 15.90 /o,7o A 16.46 | (5,4기10,77 |Arfal 6.5 1657 (6.08 lo.P ー2c |lo.nlrne 23 1l.60 .81 16 35 6.44 6,56 1IZ P 702 /6,3314 Par pe 3) Caleulate the volume of YOUR base that you need to add to reach the equivalence point in 61713 341 ta 1 intu reus)%!the volume from step 3 hdut Calculate the buret reading when you should reach the equivalence point in the titration (initial buret reading mL) 5) Calculate the buret reading at which you need to start drop-by-drop (top 4- 16.11-1-15.11 6) Start titration!! a. Add 1 mL at a time until you reach the volume you calculated in step 5 i. Record the actual volume from the buret after cach addition, don't just add I to the previous i. Also record pH and color after every addition. b. When you reach the volume you calculated in stoo 5 staur ading I drop at a time until you measure the equivalence point. (This might not equal the volume calculated in step 4) 15.11 c. Calculate the buret volume at which you can stop adding drop-by-drop d. Continue to add I drop at time until you reach the buret volume calculated in step 6 1. om Add~1 mL at a time for an additional 6 mL e.

Answer 1

Soluti CVen 니 obsered PH3 3 for calcl ated pti - initially Volume of HC 25 m 1000mし -Tota , volumeこO. Ч3425ml: 25-113m ニD.IOKIS m S 443 m 1 0 0-937 u) b Observed pH atte, D. 16 5 2, M Naotl チml,

Theq react initial밍 25% -TO tai 35十7.32ml Volume -final concentration o HcI 4236 . 0- 0448 PH00 o4446)5) 35 to o 0 1-35 R Sm, 103 tHcl Total olume - 2ml ina conceorat n o Hc8 니ld) volume. .O.1 NaO Hat equin lence po.t

Ve 5.62ml 78933 어 .this prin { p" obse' Ved·ご9.89 8.ודר 2 25 0 103mmol c le 40.62 4.98 -49902 3e4 uivalento in 1he R5xO.ID 3 2 :ロ.16 25 XVea " /o lum t (at-eq peen t) t. Na0H ' t5. 6174 3 34,侧 uret rea ding blame at stcp 315 61T4354m rotal buret eadt beach it

equuialence Dot G m 5) burret ieading at Start drop b dro P Step-4-lml)