How many grams of glucose must be added to 275 g of water in order to prepare percent by mass concentration of aqueous glucose solution 1.30% ?
1 Answer
Explanation:
The idea here is that the solution's percent concentration by mass tells you the number of grams of solute, which in your case is glucose, present for every
A solution that is
So the question is actually asking about the number of grams of glucose that must be added to
If you take
x quad "g" + "275 g" = (x + 275) quad "g"
So you know that
This means that you have
(x color(red)(cancel(color(black)("g glucose"))))/((x + 275) color(red)(cancel(color(black)("g solution")))) = (1.30 color(red)(cancel(color(black)("g glucose"))))/(100. color(red)(cancel(color(black)("g solution"))))
Rearrange and solve for
100. * x = 1.30 * x + 1.30 * 275
98.7 * x = 357.5 implies x = 357.5/98.7 = 3.6221
Rounded to three sig figs, the number of sig figs you have for your values, the answer will be
color(darkgreen)(ul(color(black)("mass of glucose = 3.62 g")))