Question

Question #4e924

Answer 1

`"98 g water"`

Explanation:

You know that a `"2% m/m"` sucrose solution must contain `"2 g"` of sucrose for every `"100 g"`, so right from the start you can say that the total mass of the solution will be equal to `"100 g"`.

Now, you're making this solution by adding `"2 g"` of sucrose to water, so use the total mass of the solution to figure out exactly how much water you need

`"2 g sucrose"color(white)(.) + xcolor(white)(.)"g water" = "100 g solution"`

You will end up with

`x = "100 g" - "2 g"`

`x = "98 g"`

You got to the answer by subtracting your value from a constant, i.e. from `"100 g"` of solution, so the answer must not have any decimal places because of the fact that `"2 g"` of sucrose doesn't have any decimal places.

Therefore, you can say that in order to make a `"2% m/m"` sucrose solution, you need to add `"2 g"` of sucrose to `"98 g"` of water.