Question

How much water should be added to 15 grams to obtain 15 percent salt solution

Answer 1

Solution:

The mass by mass percentage of a solution is given by the following relation

Mass percentage = $\sf\Large\ \frac{Mass of Solute}{Mass of Solution}$ × 100

where,

Mass of solution = mass of solute + mass of solution

Here, mass of the solute (i.e. salt) = 15 g and the required concentration of the solution is 15 %.

Let the mass of water be a grams.

So,

$\sf\ 15 = [15 / (15 + a)] X 100$

Solving for a, we get

$\sf\ a = (100 - 15)g$

$\dashrightarrow\: \underline{\boxed{\bf{\red{= 85 g}}}}$

Answer 2

Answer:

85g

Explanation:

concentration of solution =[mass of solute/ mass of solution]*100

15=[15/15+x]*100

15+x=[15/15]*100

x=100-15

x=85g