Question

Ranchi prepared a salt solution with concentration 11.11% (mass by mass percentage) in 320 g of water. Abhinav prepared a salt solution by dissolving the same amount of salt

(as used by Ranchi), but in 160 g of water. What is the approximate concentration in

mass by mass percentage) of the solution prepared by Abhinav?​

Answer 1

Given info : Ranchi prepared a salt solution with concentration 11.11% (mass by mass percentage) in 320 g of water. Abhinav prepared a salt solution by dissolving the same amount of salt

(as used by Ranchi), but in 160 g of water.

To find : the approximate concentration of the solution prepared by Abhinav.

Solution : percentage conc. = Mass of salt/mass of solution × 100

let mass of salt used by Ranchi is X g

so, 11.11 % = x/(x + 320) × 100

⇒11.11/100 = x/(x + 320)

⇒100x = 11.11x + 3555.2

⇒x = 3555.2/88.89 = 39.99 ≈ 40g

So the mass of salt is 40g

Now conc of salt prepared by Abhinav = mass of salt/mass of solution × 100

= 40g/(40g + 160g) × 100

= 40/200 × 100

= 20%

Therefore the concentration of salt solution prepared by Abhinav is 20% (mass/mass )