Question

A solution contains 40 g of common salt in 160 g of
water. The amount of water that should be added in
the solution to reduce its concentration to half will be
(approximately)​

Answer 1

Explanation:

mass of salt / solute is 40g

mass of solution is 160 + 40 = 200

mass by percentage is 40 /200 *100 = 20=

this is what i know i hope it gelp you

Answer 2

Given:

A solution contains 40 g of common salt in 160 g of water.

To find:

The amount of water that should be added in

the solution to reduce its concentration to half.

Solution:

The amount of solute is 40 grams.

The mass of the solution is 40+160=200 grams.

Hence the concentration of the solution is 40/200×100=20%.

Now the concentration is reduced to half. The new concentration is 20%/2=10%.

The amount of solute is 40 grams.

Let the amount of water added be x grams.

$\frac{40}{200 + x} \times 100 = 10 \\ 4000 = 2000 + 10x \\ 10x = 2000 \\ x = 200$

Hence 200 grams of water is added.