Ethanol is widely used in laboratories to perform various disinfection procedures and to maintain a clean, contamination-free working environment. During experiments and routine laboratory work, maintaining sterility is essential to prevent unwanted microorganisms from interfering with results.
At the correct concentration, ethanol is highly effective for disinfecting laboratory benches, equipment, and even hands during experimental procedures. In particular, 70% ethanol is commonly used to clean work surfaces and as a hand disinfectant because it effectively eliminates bacteria, fungi, and many viruses.
Research shows that 70 % Ethanol is effective in killing bacteria, viruses and also fungi because the amount of water present in the concentration allows slow evaporation and improves protein denaturation.
N/B: The preparation of 70% ethanol depends on the concentration of your stock solution. For example, if you are working with a 90% or 95% ethanol stock solution, the dilution calculation will differ.
In this example, we will prepare 100 mL of 70% ethanol using a 95% ethanol stock solution, demonstrating the correct calculation and dilution method.
Materials Needed
5. Labels
Formular to use
C1V1=C2V2
Where:
C1 = Initial Concentration
V1 = Volume of ethanol needed
C2 = Final Concentration (70%)
V2 = Final Total Volume
Example on the calculation:
V1=C2xV2/C1
V1=70x100/95
V1= 73.7 ml – Volume of Ethanol needed
Procedure
- Measure 73.7 mL of 95% ethanol.
- Pour into a 100 mL conical flask.
- Add distilled water slowly until the total volume reaches 100 mL.
- Mix gently.
- Label: 70% Ethanol, date prepared.
- Mix gently.
Your solutions will be ready to use.
Our tutorial on how to make 70% Ethanol solution in the laboratory has a step by step compressive guide on the topic. Click the link to watch.
Conclusion
Ethanol preparation in the lab is easy and direct when you understand the dilution formula and follow proper laboratory procedures. A low concentration of the solution is more effective than a higher one.
Remember doing regular disinfection in the laboratory is essential in maintain a clean environment, that’s why ethanol is needed.