You receive the following prescription: Benzalkonium Chloride: 50 mL Distilled Water: QS 500 mL M.Ft Solution Sig: Use as directed Supplies Available: Benzalkonium Chloride 25% (V/V) stock solution, purified water. Calculate:
a) The total quantity of benzalkonium chloride 25% stock solution, in milliliters, that is needed to compound this prescription.
b) The total quantity of distilled water, in milliliters, that is needed to compound this prescription.
c) Express the concentration of benzalkonium chloride that is found in this prescription in ratio strength.