Final answer:
The statement is false; a normal saline solution contains a 0.9% mass/volume percentage of NaCl, not 9%. It's roughly equivalent to a 0.16 M solution, which matches the salinity of human body fluids.
Step-by-step explanation:
The statement that a normal saline solution consists of a 9% solution of NaCl is false. A typical normal saline solution used for intravenous injections has a concentration of 0.9% mass/volume of NaCl, which means it contains 9.0 grams of sodium chloride in every liter of solution.
This concentration is equivalent to a 0.16 M (molar) solution, which is also close to the physiological saline concentration found in the human body. To prepare a normal saline solution, one would dissolve the appropriate amount of NaCl in water to achieve this concentration. For example, calculating the mass of sodium chloride needed to prepare 250 mL of 0.9% saline would involve using the mass/volume percentage formula.
A physiological saline concentration for purposes like contact lenses is also set to match the 0.16 M concentration which resembles the salinity of human body fluids. When referring to physiological saline concentration, it's important to note that this is indeed the concentration used to match the sodium chloride levels in our bodies and is crucial for maintaining cell integrity when solutions are introduced intravenously.