ocr: 18.42 (a) cO? is a relatively strong Bronsted base and produces OH in aqueous solution according to the hydrolysis reaction: CoS(aq) + H,O0) - HCO(aq) + OH(aq), K, = 1.8X10 If enough OH'(aq) is produced to exceed Kop tor Mg(OH)2 the solid will precipitate. (b) 150 1kgs mg soln Mg2 X 1000 1gMg2 mg Mg? X 1kgs 1Lsoln soln X 24.3 1mol 9 Mg2+ Mg" == 6.2x103 M Mg2* 5.0 g NazCOs X 1r mol CO3 == 0.047 M CO3 1.0Lsoln 106.0 9 Na2COs Kb = 1 1.8 x 104 M [COSI [HCOIIOH] x2 0.047 i X = [OH] = 2.9 x 103 M (This represents 6.2% hydrolysis, but the result will not be significantly different using the quadratic ...
