Question

What is the final volume in milliliters when 0.781 L of a 43.4 % (m/v) solution is diluted to 20.8 % (m/v)?

Answer 1

`V_2=1.63L`

Step-by-step explanation:

Hello,

In this case, by using the dilution equation wherein we assume that the mass of the solute remains unchanged:

`V_1C_1=V_2C_2`

We must compute the the final final given the initial volume and the both the initial and final concentrations in %m/v as shown below:

`V_2=(V_1C_1)/(C_2) =(0.781L*43.4\%)/(20.8\%) \\\\V_2=1.63L`

Best regards.

Answer 2

1629.33 mL

Step-by-step explanation:

To do this, we need to use the correct expression. WE are talking about %m/V, and the expression for this is:

%m/V = m solute / V solution * 100

We have the volume of solution, and the initial concentration. With these data we can calculate the mass of solute, which will remain constant when the solution is being dilluted. From above we can solve for mass of solute:

m solute = %m/V * V solution / 100

Replacing we have:

m = 43.4 * 0.781 / 100 = 0.3389 g

With this value, we solve for V of solution now, but with the concentration of 20.8%:

V solution = m solute / %m/V * 100

V solution = 0.3389 / 20.8 * 100

V Solution = 1.62933 L

This will be the final volume in liters. In mililiters is:

V = 1629.33 mL