# Question #4e924

Jul 30, 2017

$\text{98 g water}$

#### Explanation:

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

Now, you're making this solution by adding $\text{2 g}$ of sucrose to water, so use the total mass of the solution to figure out exactly how much water you need

$\text{2 g sucrose"color(white)(.) + xcolor(white)(.)"g water" = "100 g solution}$

You will end up with

$x = \text{100 g" - "2 g}$

$x = \text{98 g}$

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

Therefore, you can say that in order to make a $\text{2% m/m}$ sucrose solution, you need to add $\text{2 g}$ of sucrose to $\text{98 g}$ of water.