Question

2. CHEMISTRY How many liters of 15% acid and

33% acid should be mixed to make 40 liters of 21%
acid solution?
Concentration
of Solution
Amount of
Solution (L)
Amount
of Acid
15%
33%
у
21%
40

Answer 1

To make a 40-liter solution of 21% acid, you will need approximately 26.7 liters of 15% acid and 13.3 liters of 33% acid.

Step-by-step explanation:

To find out how many liters of 15% acid and 33% acid should be mixed to make 40 liters of 21% acid solution, we can use the dilution equation. Let x be the amount of 15% acid in liters and y be the amount of 33% acid in liters. The equation can be set up as follows:

0.15x + 0.33y = 0.21(40)

0.15x + 0.33y = 8.4

We also know that x + y = 40 (since the total volume of the solution is 40 liters).

Now we can solve these two equations simultaneously to find the values of x and y.

Using substitution method, we can solve for y in terms of x:

y = 40 - x

Substituting the value of y in the first equation:

0.15x + 0.33(40 - x) = 8.4

0.15x + 13.2 - 0.33x = 8.4

-0.18x = -4.8

x ≈ 26.7

Substituting the value of x to find y:

y = 40 - 26.7

y ≈ 13.3

Therefore, approximately 26.7 liters of 15% acid and 13.3 liters of 33% acid should be mixed to make 40 liters of 21% acid solution.

Answer 2

26²/₃ liters of 15% acid and 13¹/₃ liters of 33% acid

Step-by-step explanation:

Concentration Amount of Amount

of Solution Solution (L) of Acid

15% x 0.15x

33% y 0.33y

21% 40 0.21•40

x + y = 40 ⇒ x = 40 - y

0.15x + 0.33y = 0.21•40

0.15(40 - y) + 0.33y = 0.21•40

6 - 0.15y + 0.33y = 8.4

0.18y = 2.4

y = 13¹/₃

x = 40 - 13¹/₃ = 26²/₃