Question

Besar PH larutan 0,74 gram Ca(OH)2(ArCa=40, O=16, dan H= 1) dalam 500 mL larutan adalah

Answer 1

M Ca(OH)2 = massa/mr x 1000/v
M Ca(OH)2 = 0,74/74 x 1000/500 = 0,02 M

Ca(OH)2 ==> Ca2+ + 2OH-
0,02M.........0,02M.....0,04M

pOH = -log[OH-] = -log 0,04 = 2-log 4
pH = 14-(2-log 4) = 12+log 4