In: Chemistry
Potassium chloride for injection comes in 60 ml vials containing 2 mEq/mL. how many milligrams of KCL are in each vial. im not sure what a mEq, is plus i need the steps on how to do the question. thank you
mEq means milli equivalents.
Sometimes the concentration of an electro;lite is expressed in terms of milli equivalents.
Any electrolite with one mole of cation and one mole of anion has same number of milli equivalents as that of the milli moles. For example one milli mole of KCl has one milli equivalent of K+ and one equivalent of Cl-.
Coming to the question, what we have given with is a 60 ml KCl solution whose concentration is 2 mEq/mL or 2 milli mole/ml or 0.002 mole/1 liter.
That means it has 0.002 moles of KCl per 1000 ml solution.
We have here 60 ml solution, then the number of moles of KCl per 60 ml solution = (60 / 1000) x 0.002
= 0.00012 moles.
Now we got the number of moles of KCl in given 60 ml sample solution.
Since moles = mass / molar mass
mass of KCl = moles x molar mass
molar mass of KCl = 74.5513 g/mole
mass of KCl = = 0.00012 moles x 74.5513 g/mole
= 0.1491026 grams
mass of KCL are in each vial = 149.102 milli grams