The volume of Mrs. X's plasma was 3 liters before Ed administered the IV. Assume that there was a complete mixing of the administered water with her plasma but no mixing with her interstitial fluid. Calculate Mrs. X's plasma osmolarity after the infusion mixed with her plasma but before any water entered the rbcs. Hint: What was the total of mOsm in her plasma before the infusion? Once the plasma volume is increased by 1 L, the total of mOsm remains the same, but the volume has changed. Now what is the new osmolarity (mOsm/L?) Does this fit your prediction, above? Mrs. X got much worse after the Ed's treatment, so the resident was called. She drew some blood from the patient and centrifuged it. The supernatant above the packed rbcs was pink. The resident then decided to infuse a sucrose solution into the patient (the rbc membrane is impermeable to sucrose). 3. Why was the plasma pink? 4. Had Ed given Mrs. X a sucrose solution instead of water, he might have helped her. What concentration of sucrose solution should he have administered to leave her rbc volume unaffected?