Caption:
Chromium (III) hydroxide precipitate. Test tube with 0.15M chromium (III) potassium sulfate solution (left frame) has a 1M solution of sodium hydroxide (NaOH) added. As a result, chromium (III) hydroxide precipitate (Cr(OH)3) is formed (right frame): KCr(SO4)2 + NaOH -> Cr(OH)3 + KNaSO4 + Na2SO4.