How do I prepare 30% v/v ethanol from 95% ethanol?
Thanks.
Would 100 mL of 95% EtOH diluted to 316.6 mL (assuming volumes are additive) do it?
Hi, how do I do the calculation?
Thanks
95/x = 30
x = 3.167
1 mL to 3.167 mL or
10 mL to 31.67 mL or
100 mL to 316.7 mL or
1000 mL to 3167 mL.
95% x (100/3.167) = 30%
To prepare a 30% v/v (volume/volume) ethanol solution from 95% ethanol, you will need to dilute it with some amount of water. Here's how you can calculate the amount of ethanol and water needed:
Let's assume you need to prepare 100 mL of the 30% v/v ethanol solution.
Step 1: Determine the volume of ethanol required:
Given that the volume/volume percentage of ethanol you require is 30%, you can calculate the volume of ethanol needed using the formula:
Volume of ethanol = (Volume of desired solution) x (Percentage of ethanol required)
In this case, it will be:
Volume of ethanol = (100 mL) x (30/100) = 30 mL
Step 2: Calculate the volume of water needed:
To find the volume of water, subtract the volume of the ethanol from the total volume of the desired solution:
Volume of water = (Volume of desired solution) - (Volume of ethanol)
Volume of water = 100 mL - 30 mL = 70 mL
So, to prepare 100 mL of a 30% v/v ethanol solution from 95% ethanol, you need to mix 30 mL of 95% ethanol with 70 mL of water.
Note: When preparing solutions, always add the lesser concentration component (in this case, water) to the higher concentration component (ethanol) and not the other way around, to ensure accuracy.