How does the pH affect the solubility of sulfide compounds? Select the correct answer below: Most sulfides are soluble in basic conditions but not acidic conditions. Most sulfides are soluble in acidic conditions but not basic conditions. When the pH is low, the concentration of S2− is high, so only compounds with a large Ksp will precipitate. When the pH is low, the concentration of S2− is small, so only compounds with a small Ksp will precipitate.