A glucose solution is isopiestic with blood. What is the osmolarity of glucose solution? — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

Blood is isotonic (isopiestic) with 0.9% (w/v) NaCl solution. The concentration of this NaCl solution is 9 g/L. Molarity $= 9 / 58.5 = 0.1538$ M. Since NaCl yields 2 ions ($i=2$), the osmolarity is $2 \times 0.1538 = 0.3076$ M $\approx 0.31$ M. The glucose solution must have the same osmolarity to be isopiestic. Therefore, correct answer is A.