Question

A health clinic uses a solution of bleach to sterilize petri dishes in which cultures are grown. The sterilization tank contains 150 gal of a solution of 4% ordinary household bleach mixed with pure distilled water. New research indicates that the concentration of bleach should be 8% for complete sterilization. How much of the solution should be drained and replaced with bleach to increase the bleach content to the recommended level?

Answer 1

Answer:

6.25 gallons solution should be drained and replaced 6.25 gallons with bleach to increase the bleach content to the recommended level.

Explanation:

Volume of the solution in the tank = 150 gal

Percentage of bleach in solution = 4%

Volume of bleach present = (4% of 150)gal

Let the volume of solution removed = x

Volume of bleach removed = (4% of x )gal

Desired percentage of bleach solution = 8%

Volume of bleach in 8% solution = 8% of 150 gal

(4% of 150)gal +x - (4% of x )gal = 8% of 150 gal

(4% of 150) +x - (4% of x ) = 8% of 150

$6+x-0.04x=12$

$0.96x=6$

x = 6.25

6.25 gallons solution should be drained and replaced 6.25 gallons with bleach to increase the bleach content to the recommended level.