Question

How many milliliters of a 1:5000 w/v solution of the preservative lauralkonium chloride can be made from 125 ml of a 0.2% w/v solution of the preservative?

a) 25 mL
b) 50 mL
c) 100 mL
d) 250 mL

Answer 1

To make a 1:5000 w/v solution from 125 mL of a 0.2% w/v solution, the volume of the solution that can be made is 250 mL. Therefore, the correct answer is D.

Step-by-step explanation:

To determine the amount of 1:5000 w/v solution that can be made from 125 mL of a 0.2% w/v solution, we can use the relationship between the concentrations and volumes of the two solutions. In a 1:5000 w/v solution, the ratio of the mass of the solute to the volume of the solution is 1:5000. Since the concentration of the solute in the 0.2% w/v solution is 0.2 g/100 mL, we can calculate the mass of solute in 125 mL of this solution.

Mass of solute = 0.2 g/100 mL x 125 mL = 0.25 g

Now, we can use the ratio to calculate the volume of the 1:5000 w/v solution that can be made from this amount of solute:

Volume of 1:5000 w/v solution = (0.25 g/1) x (5000 mL/1 g) = 1250 mL = 1250 mL