Texas Class A Barber Written ExamSanitation, Disinfection, and SafetyHard
A barber is preparing a 1:100 dilution of a concentrated disinfectant. If the container holds 1 gallon (128 fluid ounces) of water, how much disinfectant concentrate should be added?
- A128 fluid ounces
- B1.28 fluid ounces
- C12.8 fluid ounces
- D0.128 fluid ounces
Show answer & explanationAnswer & explanation
Correct answer: B. 1.28 fluid ounces
A 1:100 dilution means 1 part concentrate to 100 parts water. To find the amount of concentrate, divide the total volume of water by 100. 128 fluid ounces (water) / 100 = 1.28 fluid ounces of concentrate.
Why the other options are wrong
- A. This would be a 1:1 dilution, far too strong and potentially hazardous.
- C. This would be a 1:10 dilution, too strong.
- D. This would be a 1:1000 dilution, too weak.
Dilution Ratio Calculation
The mathematical process of determining the correct amount of concentrate to mix with a given volume of diluent (e.g., water) to achieve a specified ratio.
- Ratio X:Y means X parts concentrate to Y parts diluent.
- Crucial for disinfectant efficacy and safety.
- Incorrect dilution can render disinfectant ineffective or harmful.
Memory trick: Water divided by ratio equals concentrate needed.