Question

Solution A consists of a 0.20 M aqueous solution of aspirin (acetylsalicylic acid, C9H&O4) at 25 °C. Calculate the pH of Solution A. The pKa of aspirin is 3.52 HO At 25 °C, 1.00 L of Solution B consists of 40.4 g of sodium acetylsalicylate (NaC9H7O4) dissolved in water. Calculate the pH of Solution B

Answer 1

» Suppose Archet sahraytre and is HA- 37 elizgoriates as - HA gut + Á ku= [ast] [A] suppose [at] =[A"}=x [ HA? As Pkuz 3.52 kaz hogerkan a-log (352) Kon 3.099x noh 3.019x10h= x2 Ka= 3.019 x909 0,2 m ***2 = 30019 21 % 012. m "x² = 60 39x105 *=7.99 x ? Mail - [MM] =7.37xia? M - 8m = -19% (1 32 3 4 5. m = 2.10 pn = 2010 solution = 2.10

acetyl Sutingladre suppose in water is sodrum as B it dessoriates B + mo - HB + out i mb- [MB] [ on} [B] Now ka x 14 = kw aloxio kb 10*10 i, deb - ka doox tö14 30049 x 104 Kb= 3.31 x 10 As molar mass fuchnum acetyl Salmingtante = 202.14 gminale moles of soeknum ueryl sealicylate = 40ch gm 202.14 googmole = 0.1998 males : Dolggg moles in 1 L Mo 0.1998 m solaton,

" by adding verlues in my equation - If suppose [+] = [oxi?. [HB] [ori) [8] 3-31x10" = x2 0.1998 m cix2= 3.39x16" x 0.1998 m = 6.618 x 1012 x² = 8.618x1012 x= v 6.69841012 2.57 x 166 [on]: 257x166 i porta alog (2.57 x166) pos= 5.59 " PHI14-5.59 = 8.40 .. on of solution = 8.ho