An isotonic solution will produce an osmotic pressure of 7.84 atm measured against pure water at human body temperature (37.0 °C).How many grams of sodium chloride must be dissolved in a liter of water to produce an isotonic solution?
A)75.5 g
B)151 g
C)2.58 g
D)9.00 g
E)18.0 g

Question

Quizplus · Accepted Answer

An isotonic solution has the same osmotic pressure as body fluids. Using the formula for osmotic pressure (π = iMRT), where i for NaCl is 2, R is 0.0821 L·atm/mol·K, and T is 310 K, we can solve for M (molarity). Then, using the molar mass of NaCl (58.44 g/mol), we calculate the mass needed to achieve this molarity in 1 liter of solution, which is approximately 9.00 g.

An Isotonic Solution Will Produce an Osmotic Pressure of 7