Question

A chemist needs to obtain a 75% acid solution. How many Ounces of a 20% acid solution must be mixed with 20 ouncesof an 90% acid solution to obtain

a 75% acid solution? (round to the nearest hundredth if necessary)

Answer 1

Answer: 5.4545 ounces

Explanation:

Given the following :

Acid solution required = 75% acid solution

Let the number of ounces of 20% acid solution required = s

Then total ounces acid required can be expressed as :

=0.20s + 0.90 x 20

= 0.20s + 18

While the total ounces required is :

s + 20

Hence, (total ounces of acid / total ounces) = 75% acid solution

= (0.2 + 18) / (s + 20) = 0.75

= 0.2s + 18 = 0.75( s + 20)

0.2s + 18 = 0.75s + 15

18 - 15 = 0.75s - 0.2s

0.55s = 3

S = 3 / 0.55

= 5.4545 ounces