Plasma is the fluid portion of blood. The concentration of acetylsalicylic acid (aspirin, C₉H₈O₄, molar mass = 180. g/mol) in your plasma is found to be 2.99 * 10^-4 M after you take two tablets of aspirin. If the volume of your plasma is 5.85 L, what is the molality, m, of aspirin in your blood (Assume density of plasma is 1.00 g/mL.) A) 4.99 * 10^-4 m B) 3.99 * 10^-4 m C) 2.99 * 10^-4 m D) 1.99 * 10^-4 m E) None of the above

Question

Quizplus · Accepted Answer

Molality (m) is calculated using the formula: m = moles of solute / kg of solvent. Since the density of plasma is 1.00 g/mL, 5.85 L of plasma is equivalent to 5.85 kg. The molality is the same as the molarity in this case because the volume in liters is numerically equal to the mass in kilograms.

Plasma Is the Fluid Portion of Blood