# Question 64952

Nov 25, 2016

$\text{2.6% m/v}$

#### Explanation:

The key to any dilution calculation is the fact that the amount of solute remains unchanged. The only thing that changes when a solution is diluted is the amount of solvent.

Now, an $\text{11% m/v}$ solution contains $\text{11 g}$ of solute for every $\text{100 mL}$ of solution. This means that your initial sample will contain

175 color(red)(cancel(color(black)("mL solution"))) * "11 g solute"/(100color(red)(cancel(color(black)("mL solution")))) = "19.25 g solute"

This is exactly how much solute will be present in your diluted solution. You dilute the initial solution by adding water, which is your solvent.

To find the mass by volume percent concentration of the diluted solution, use the fact that it contains $\text{19.25 g}$ of solute in $\text{750 mL}$ of solution.

Your goal here is to figure out how much solute will the diluted solution contain in $\text{100 ML}$ of solution

100 color(red)(cancel(color(black)("mL solution"))) * "19.25 g solute"/(750color(red)(cancel(color(black)("mL solution")))) = "2.6 g solute"

Therefore, you can say that the diluted solution has a mass by volume percent concentration of

color(darkgreen)(ul(color(black)("% m/v" = 2.6%)))#

The answer is rounded to two sig figs.