When preparing a 0.9% sodium chloride solution, if the volume of water needed is known, what is the concentration of sodium chloride in the solution?

To determine the concentration of sodium chloride in a 0.9% sodium chloride solution, it’s essential to understand what the percentage signifies. A 0.9% solution means that there are 0.9 grams of sodium chloride present in 100 mL of the solution.

When you prepare a solution and you know the volume of water needed, you would then measure out the appropriate amount of sodium chloride to achieve the desired concentration. Since the question specifically states that it is a 0.9% sodium chloride solution, you would aim for that concentration. Therefore, the sodium chloride component remains consistently at 0.9 grams per 100 mL, confirming that the concentration is indeed 0.9%.

This directly corresponds with the task at hand – if the prepared solution is labeled as 0.9% sodium chloride, this indicates that the solution will maintain that concentration regardless of the volume being prepared, as long as the correct ratio of sodium chloride to water is adhered to. Thus, the concentration of sodium chloride in the solution is accurately described as 0.9%.