Question

The concentration (w/w%) of a 200 g solution of common salt is 10%. If 20 g more water is mixed in it then its concentration becomes

Answer 1

Answer:

Given,

The concentration (w/w%) of common salt = 10%

Mass of the solution = 200 grams

To find,

The concentration if 20 grams of water is added to the solution.

Solution,

Let,the mass of the solute or the common salt = x grams

[Assume, x as a variable to do the further mathematical calculations.]

Now,we have to apply the w/w% concentration formula,

Concentration (w/w%) = 100 × Mass of solute/Mass of solution

10 = 100 × x/200

x/2 = 10

x = 20

Mass of solute = 20

Now, mass of the solution after water addition = 200+20 = 220 grams

So,final concentration (w/w%) = 100 × 20/220 = 9.09%

Hence, the final concentration (w/w%) will be 9.09% or Option 3.

Explanation: