Question

A chemist has two solutions of HNO 3. One has a​ 40% concentration and the other has a​ 25% concentration. How many liters of each solution must be mixed to obtain 120 liters of a 30​% ​solution?

Answer 1

40 Liter of 40% solution and 80 Liter of 25% solution should be mixed to obtain 120 liters of a 30​% ​solution

Step-by-step explanation:

Let the volume of the 40% and 25% solution be x and y.

x + y = 120....(1)

Percentage of the
`HNO_3` will equal to the sum percentage of
`HNO_3` in x anf y volumes.

`40\%of x+25\%of y=30\% of 120`

`0.40* x+0.25* y=0.30* 120`

8x + 5y = 720....(2)

Solving equation (1) and (2) we get:

x = 40 L , y = 80 L

40 L of 40% solution and 80 L of 25% solution should be mixed to obtain 120 liters of a 30​% ​solution