Question

Question #3470c

Answer 1

`"34 g TSP"`

Explanation:

A solution's mass by volume percent concentration, `"% m/v"`, tells you the number of grams of solute present for every `"100 mL"` of solution.

In your case, a `"1.7% m/v"` trisodium phosphate solution will contain `"1.7 g"` of trisodium phosphate, the solute, for every `"100 mL"` of solution.

You know that the solution has a total volume of

`2 color(red)(cancel(color(black)("L"))) * (10^3color(white)(.)"mL")/(1color(red)(cancel(color(black)("L")))) = 2 * 10^3` `"mL"`

which means that it must contain

`2 * 10^3 color(red)(cancel(color(black)("mL solution"))) * overbrace("1.7 g TSP"/(100color(red)(cancel(color(black)("mL solution")))))^(color(blue)("= 1.7% m/v TSP solution")) = color(darkgreen)(ul(color(black)("34 g TSP")))`

in order to have the desired mass by volume percent concentration.

The answer is rounded to two sig figs.

Remember, you can use the known percent concentration of a solution as a conversion factor because solutions are homogeneous mixtures, which means that they have the same composition throughout.