The solubility product constant Ksp is used to determine the solubility of a sparingly soluble salt in water. However, the Ksp value provided 36 is incorrect for sodium chloride NaCl . NaCl is a highly soluble salt, and its solubility does not depend on the Ksp value. Instead, we can use the known solubility value for NaCl in water at 25C.The solubility of sodium chloride NaCl in water at 25C is approximately 357 g/L. This means that 357 grams of NaCl can dissolve in 1 liter of water at 25C.