A saline solution is administered intravenously to patients who cannot take fluid orally and are in danger of dehydration. The osmotic pressure of this solution must match that of blood to prevent hemolysis or crenation of blood cells. What mass of sodium chloride (58.44 g/mol) is needed to produce 100.0 mL of saline solution with an osmotic pressure of 7.83 atm at a body temperature of 37°C?
A) 0.899 g
B) 8.99 g
C) 18.0 g
D) 1.80 g
E) 0.450 g

Question

Quizplus · Accepted Answer

The osmotic pressure (π) is given by the formula π = iMRT, where i is the van't Hoff factor (2 for NaCl), M is molarity, R is the gas constant (0.0821 L·atm/mol·K), and T is temperature in Kelvin (310 K for 37°C). Solving for M and then converting to mass gives approximately 0.899 g of NaCl.

A Saline Solution Is Administered Intravenously to Patients Who Cannot