Question

What volume of 50% acid solution should be combined with pure acid to create 80ml of an 85% acid solution?

A) 25 ml
B) 30 ml
C) 35 ml
D) 40 ml

Answer 1

The volume of 50% acid solution needed to create an 85% acid solution is 35 ml.

Step-by-step explanation:

To find the volume of the 50% acid solution needed, we can use the concept of mixing solutions. Let's assume that x ml of the 50% acid solution is needed. Since the final volume is 80 ml, we can set up the equation:

(50% acid)(x ml) + 100%(80 ml - x ml) = 85%(80 ml)

This equation represents the mixture of the 50% acid solution (x ml) and pure acid (80 ml - x ml) to create a final solution with 85% acid concentration. Solving this equation will give us the value of x, which is the volume of the 50% acid solution needed.

Using this method, we find that the correct answer is 35 ml (option C).