Question

3. Morin acid, HsCisHsO7 is a yellow pigment, found in Osage oranges, thatt can be used to test for aluminum ion. A 25.00 mL sample of a HsC1sHsO7 solution was titrated completely with 18.75 mL of 0.1347 M potassium hydroxide solution. Write the balanced chemical equation. (4 pts.) а. b. Calculate the molarity of the HsCisHsO7 solution. (7 pts.) Dithionite (S2O42) has been studied as a way of removing toxic chlorate ion from water, by the following reaction. 4. Assign oxidation state (on the line) for each of the atoms in the net ionic oxidation-reduction reaction. Show work under the line. (10 pts.) a. 10 SO2 (aq) +8 H'(aq) + Cla(g) 5 S20P(aq)+2 CIO; (aq) + 4 H20(e) OS Which atom is being reduced? (1 pt.) b. Which atom is being oxidized? (1 pt.) с. What substance is the oxidizing agent? (1 pt.) d. t

Answer 1

(3) Morin acid, HS CisHs Oy have five ionisable protons (a) HS Cists Oy + 5 koH Kg Cis Hs Oy to (6) from the above balanced equation 1 mele of morin and reacts with 5 moles of koH. Millimeles of KOH = 5 x millimelus of Morin acid MiVI - 5 M₂ V. M. - Concentration of Koh V. - Volume of KOH 0.1347 Mx 18.75 mL = 5xM₃ x 25 mL M₂ = Conc of Morinacid 0.1347 M x 18.75 mL = M2 V = volume of Morin 5x as mL acid . 10.0202m = M2. * Molarity of HSCISHS on = 0.0202 M) Molarity of morin acid can also be calculated as: 5 me koH reacts with 1 mele Morin acid. 0.1347 *18.75mmal react with : 0.1347 X18-7 Smmel Acid Molarity of H5C1SHsOy - Milli Moles Volume (mL) = 0.1347 & 18.75 mmel. SX 25 mL Hs G5 H5 07 = 0.0202 M Molarity of

4)(a) 5S₂Oy2 + 20103 +440 1050? + 8H + C₂ +3-2 +5-2 +1 -2 +4 -2 t o S₂04²- - 2x + 4 (-2) = -2 - 2x = -2+8 x=+3. clor = x + 3(-2) = -1 x= -1 +6 = +5 Soz 2- = x+3(-2) = -2 x = -2+6 = +4. (b) 'S204? → Sos? + e Coxidation). . CeO₂ + së - Cl (reduction). Chlorine (ce) atom is being reduced from +5 state to zero. (c) Sulphur istom is being oxidised from +3 to +4. (d) Atom which is reduce will the oxidise other atom. Such type of atom containing substance is known as oxidizing agent. ClO3 is the oxidizing agent.