Question

A Pedialyte solution contains Na+ 41 mEq/L , K+ 24 mEq/L , Cl− 34 mEq/L , citrate3− 31 mEq/L , and glucose (C6H12O6) 25 g/L .

Part A

What is the total positive charge of the electrolytes?

Part B

What is the total negative charge of the electrolytes?

Part C

What is the osmolarity (Osm ) of the solution?

Answer 1

Part A :

Total positive charge = Total charge of cations = Na+ + K+ = 41 + 24 = 65 mEq/L

Part B :

Total negative charge = Total charge of anions = Cl- + Citrate -3 = 31 +34 = 65 mEq/L

Part C:

Osmolarity: no of moles of particles per litre of solution

Moles = Equivalents / charge of cation/anion

Moles of Na+ = 41 mMoles   

Moles of K+ = 24 mMoles

Moles of Cl- = 34 mMoles

Moles of citrate = 31/3 mMoles = 10.33mMoles

Moles of glucose = mass / Molar mass = 25 / 180 = 0.1388 = 138.88 mMoles

Osm = Total moles / 1 Litre of solution = 0.2482