Question

Consider the titration of a 82.1 mL sample of 0.914 M HC₂H₃O₂ with 0.163 M NaOH. K_a(HC₂H₃O₂) = 1.8x10^-5

Determine the initial pH before any NaOH is added. Express your answer using 4 decimal places.

Answer 1

Solution - wulliolex е Сисоби - 82:1 0 Хо: 91 м 2 821 wiligri xo:919 шоу litect 2 15:04 00 лс. Пев Before adding NaOH there is only millimales of CH₂COOH in Vanalyte. Orolich dissocicete Ciovirze) Vaccouding to - а сис Соо + и* isci hati сисоби 0.9 1+1 -91 - 0.9 194 equilib : од 14а o.9 14 Үм, — Kaz Ссц; Соо] (n+] Си; Сосн1 0-81 Хо: 91% o-14 (1 ) • <<<1 Reu 1-з 1 14xio o-91+ 4* т 22 1-8 хот - z 1-96 94X 105 0,9 14 da 19 •699 X 1G“ 4-438 ҳ163

Hence, [ut] z o.9192 z 0.914 X 4.938 X10S z 4.056 x 10 3 puz -log(+] e-log (4.056 X163) z bog 4.056 +3loglo z 3–0.6080 z 2.3920 Henle , bu befosse adding Naon is 2.39200