NIC Nail Technician Written ExamScientific ConceptsMedium
A technician is preparing a disinfection solution using a concentrate. The manufacturer's instructions require a 1:10 dilution. If the technician needs a total of 1 gallon (128 fluid ounces) of solution, how much concentrate should be used?
- A1.28 fluid ounces
- B10 fluid ounces
- C128 fluid ounces
- D12.8 fluid ounces
Show answer & explanationAnswer & explanation
Correct answer: D. 12.8 fluid ounces
A 1:10 dilution means 1 part concentrate to 10 total parts of solution. Therefore, the concentrate makes up 1/10 of the total volume. 1/10 of 128 fluid ounces is 12.8 fluid ounces. (128 oz / 10 = 12.8 oz)
Why the other options are wrong
- A. This would be a 1:100 dilution, not 1:10.
- B. This is an arbitrary number and does not fit the dilution ratio for the total volume.
- C. This would mean 100% concentrate, not a dilution.
Dilution Ratio Calculation (1:X)
A 1:X dilution ratio means one part concentrate is mixed with X total parts of solution. To find the amount of concentrate needed, divide the total desired volume by X.
- Ratio 1:X means 1 part concentrate, X total parts.
- Total parts = (Concentrate parts + Water parts). For 1:10, it's 1 part concentrate to 9 parts water for 10 total parts.
- Calculation: Total Volume / Ratio Number = Concentrate Needed.
Memory trick: Divide the TOTAL by the RATIO number to get the CONCENTRATE amount.