Apatient requires 36 mmol of phosphate and 90 meq of potassium in their pn. the pharmacy has stock solutions of potassium phosphate (3 mmol of phosphate and 4.4 meq potassium per ml) and potassium chloride (2 meq potassium/ml). how many milliliters of potassium chloride are required?

First, we need to calculate for the volume of potassium phosphate required to meet the desired phosphate level of 36 mmol.

V potassium phosphate = 36 mmol / (3 mmol / mL)

V potassium phosphate = 12 mL

This also contains potassium in the amounts of:

V potassium in potassium phosphate = (4.4 meq / mL) * 12 mL

V potassium in potassium phosphate = 52.8 meq

Therefore the lacking amount of potassium is 90 – 52.8 = 37.2 meq

This lacking potassium must be supplied by the potassium chloride. Calculating for volume of potassium chloride:

V potassium chloride = 37.2 meq / (2 meq / mL)

V potassium chloride = 18.6 mL             (ANSWER)

law of conservation of matter