The approximate osmolarity of a 1-L solution that contains 35 g of amino acids, 200 g of dextrose, 20 g of lipids from a 20% fat emulsion, and 150 mEq and mmol of electrolytes would be __________ mOsm/L.

Question

Quizplus · Accepted Answer

To calculate the osmolarity, we need to convert all solutes to millimoles (mmoL) and add them up.

- Amino acids: We need to know which amino acids we are dealing with to calculate their mmoL, but for simplicity let's assume they are all glycine. The molecular weight of glycine is 75 g/mol. Therefore, 35 g of glycine is equivalent to 35/75 = 0.467 mol = 467 mmoL.
- Dextrose: Dextrose is another name for glucose. Its molecular weight is 180 g/mol. Therefore, 200 g of dextrose is equivalent to 200/180 = 1.111 mol = 1111 mmoL.
- Lipids: We don't need to include lipids in our osmolarity calculation because they are insoluble in water and do not ionize.
- Electrolytes: We need to convert mEq to mmoL first. Since we are not given the specific electrolytes, let's assume they are Na+, K+, Cl-, and Ca2+. Their conversion factors are:

- Na+: 1 mEq = 1 mmol
  - K+: 1 mEq = 1 mmol
  - Cl-: 1 mEq = 1 mmol
  - Ca2+: 1 mEq = 0.5 mmol (since Ca2+ has a valence of 2)

Therefore, 150 mEq of electrolytes is equivalent to:

- Na+ + K+ + Cl- = 150 mmol
  - Ca2+ = 150/0.5 = 300 mmol

The total mmoL of all solutes is:
  467 + 1111 + 150 + 300 = 2028

Therefore, the osmolarity is 2028 mOsm/L.

The Approximate Osmolarity of a 1-L Solution That Contains 35