What quantity of 80% acid solution must be mixed with a 20% solution to produce 240 mL of a 50% solution?

mL of 80% acid solution: _______
mL of 20% acid solution: _______



Answer :

To determine the quantities of 80% acid solution and 20% acid solution required to produce 240 mL of a 50% acid solution, we can follow these steps:

1. Identify the variables:
- Let [tex]\( x \)[/tex] be the volume of the 80% acid solution.
- Therefore, the volume of the 20% acid solution will be [tex]\( 240 - x \)[/tex] mL since the total volume must be 240 mL.

2. Set up the equation:
- The acid content in the 80% solution will be [tex]\( 0.80x \)[/tex].
- The acid content in the 20% solution will be [tex]\( 0.20(240 - x) \)[/tex].
- The total acid content needed in the final 50% solution will be [tex]\( 0.50 \times 240 \)[/tex] mL.

3. Write the mixture equation:
[tex]\[ (0.80x) + (0.20(240 - x)) = 0.50 \times 240 \][/tex]

4. Simplify the equation:
[tex]\[ 0.80x + 48 - 0.20x = 120 \][/tex]
[tex]\[ 0.60x + 48 = 120 \][/tex]

5. Solve for [tex]\( x \)[/tex]:
- Subtract 48 from both sides:
[tex]\[ 0.60x = 72 \][/tex]
- Divide both sides by 0.60:
[tex]\[ x = 120 \][/tex]

6. Finding the volume of the 20% solution:
- Since the volume of the 80% solution is [tex]\( x = 120 \)[/tex] mL, the volume of the 20% solution will be:
[tex]\[ 240 - 120 = 120 \text{ mL} \][/tex]

Therefore, 120 mL of the 80% acid solution and 120 mL of the 20% acid solution must be mixed to produce 240 mL of a 50% acid solution.