Question

Autosaved at 10:07 Tutored Practice Problem 17.2.6 CUSTOMERDAGRAD Prepare a buffer by direct addition Close Problem Consider how best to prepare one liter of a buffer solution with pH - 11.11 using one of the weak acid/conjugate base systems shown here. Conjugate Base K P C20,2 Weak Acid HC204 H2PO4 HCO3 K 4.19 7.21 6.4 x 105 6.2 x 10-8 4.8 x 10-11 HPO 2 00,2 10.32 How many grams of the potassium salt of the weak acid must be combined with how many grams of the potassium salt of its conjugate base, to produce 1.00 L of a buffer that is 1.00 M in the weak base? grams potassium salt of weak acid grams potassium salt of conjugate base Check & Submit Answer Show Approach When performing a calculation to determine how to make a buffer solution using an acid-base reaction, it is helpful to set up a stoichiometry table to assist in keeping track of the initial amounts of reactants and the amounts of reactants and products in the solution after a reaction takes place. Note that a stoichiometry table is different from an ICE table, which is used to keep track of changes that occur in an equilibrium system. A stoichiometry table shows the amount (in moles) of species initially in the solution, the change in candidaadilimiin. . h andmade

Answer 1

Here pH = 11-11, so choose the auld component for our bucker whose pica value is near to our pH as pla ut Har is 10.32 In buffert our base is caz- our and IS Hog _* , e@ toy Co 11-11 2 10:32 tlog ( 3 ) (6 a 10079 2 [2) 6.17 ~ 6.2 given [6] a 1.00m 2 (col) = [ 1.00 6.17 2) [A) 0.162 m. 2 [ro] porassium sak of weak acid, Kuco, moles 2 (4605) x bother mass a ICHIQ 2 0.162 moles. molar mass of Ichcą 2) mass of KHCO 0-162.moles x 100-1159 (weak and a 16-29 = 169 Potassium sal of consugate base, k o moles 2 1.00 moles mass ĄCO . 1-00 moles. molar mass 14 Co. 2 1.00 males xles 2009 grams Potassium Sall of Lovusale wise 1389