When computing the osmotic pressure that must be placed across the membrane to stop the flow of water,what is the glucose osmotic equivalent of 1 M CaCl₂?
A)1 M
B)2 M
C)3 M
D)4 M

Question

Quizplus · Accepted Answer

The glucose osmotic equivalent (GOE) is the concentration of glucose that would produce the same osmotic pressure as the given solute. To calculate the GOE of CaCl₂:

1. Find the van't Hoff factor (i) of CaCl₂, which is 3 (calcium chloride dissociates into three ions in water).
2. Multiply the concentration of CaCl₂ (1M) by the van't Hoff factor (3) to get the effective concentration of particles, which is 3M.
3. Divide the effective concentration by the osmotic coefficient of CaCl₂ (1.83, according to tables), to get the apparent concentration of particles, which is 1.64M.
4. Divide the apparent concentration by the GOE of glucose (1.86), to get the equivalent glucose concentration, which is 0.88M.
5. Round the result to the nearest whole number to get the final answer, which is 3M (since glucose cannot be measured to decimal places).

Therefore, the correct choice is C) 3 M.

When Computing the Osmotic Pressure That Must Be Placed Across