A solution of 0.9% sodium chloride is known as normal saline solution because its tonicity (308 mOsm/liter) closely correlates with the osmolality of plasma. This solution contains 154 mEq/liter of both sodium and chloride, close to normal plasma levels of 140 mEq/liter of sodium and 103 mEq/ liter of chloride.odium-containing fluids range from hypotonic (0.45% sodium chloride solution) to isotonic (0.9% sodium chloride solution) to hypertonic (5% dextrose in 0.9% sodium chloride solution).