Question

Name Solution Calculations Directions: Clearly show the setups for your calculations. 1. You wish to prepare 50.0 mL of 2.30x 102 M solution of your drug. Describe how to prepare this solution from the pure drug and deionized water. Analytical balances and volumetric flasks are available to you. (Assume that your drug dissolves in water, at least to the extent necessary for this problem.) Use complete sentences in your description of the solution preparation process. Show any required calculations you would need to make. Calculate how many milligrams of the drug are contained in 2.0 mL of a 30 % (wt/vol) solution of your drug. 2. dvuc Adderal

Answer 1

1. Volume of solution = 50 mL = 50/1000 = 0.050 L

Molarity of drug = 2.30 *10^-2 M

Molarity = Moles of drug / Volume of solution

2.30 *10^-2 M = Moles of drug / 0.050 L

Moles of drug = 2.30 *10^-2 M * 0.050 L = 0.00115 moles

molar mass of drug = 135.2062 g/mol

Moles of drug = Mass/ Molar mass

0.00115 mol = Mass of drug / (135.2062 g/mol)

Mass of drug = 0.156 g

So, If we dissolve 0.156 g of drug in enough water to make a total solution of 50 mL, then the molarity of prepared solution will be 2.30 *10^-2 M

2. wt/vol % = (Mass of drug / Volume of solution )*100%

3.0% = (Mass of drug / 2.0 mL)*100%

Mass of drug = 0.06 g = 60 mg