Question

Question #bc6af

Answer 1

`"10. mL H"_2"O"_2`

Explanation:

A solution's volume by volume percent concentration, `"v/v %"`, is a measure of the number of milliliters of solute present for every `"100 mL"` of solution.

In other words, the volume by volume percent concentration tells you how many milliliters of solute you would have if you were to pick a `"100-mL"` sample of a given solution.

In your case, you know that the solution has a `3.0%` volume by volume concentration, which means that every `"100 mL"` of this solution contain `"3.0 mL"` of hydrogen peroxide, the solute.

Now, solutions are homogeneous mixtures, which means that the same the same composition throughout. This allows you to use the percent concentration as a conversion factor to determine how many milliliters of hydrogen peroxide you'd get in `"348 mL"` of solution.

`348 color(red)(cancel(color(black)("mL solution"))) * overbrace(("3.0 mL H"_2"O"_2)/(100color(red)(cancel(color(black)("mL solution")))))^(color(blue)("= 3.0% v/v")) = "10.44 g H"_2"O"_2`

The answer must be rounded to two sig figs, the number of sig figs you have for the percent concentration.

Therefore, you will have

`color(darkgreen)(ul(color(black)("volume H"_ 2"O"_ 2 = "10. mL")))`

Answer 2

10.44mL `H_2O_2`

Explanation:

The antiseptic `H_2O_2` solution is 3.0% (v/v). This means that for every 100mL of the antiseptic solution, you have 3mL of the solute, `H_2O_2`.

3% (v/v) is the same thing as writing as `(3mL (H_2O_2))/(100mL(solution)) * 100%` so,

If for every 100mL of soln you have 3mL of `H_2O_2`, then for 348 mL you would have:

`(3mL(H_2O_2) )/(100mL(solution))` = `(x mL)/(348mL (solution))`

`cancel348mL (solution)*(3mL (H_2O_2))/(cancel100mL(solution))` = `x mL (H_2O_2)`

Answer: 10.44mL `H_2O_2`