# chemistry

posted by .

how do I prepare 50% and 70% ethanol from 95% ethanol?

• chemistry -

I assume the 50% and 70% are v/v. If so, then, 95% ethanol means you have 95 mL ethanol in a total volume of 100 mL (which doesn't necessarily mean the volume of water is 5.0 mL).To get 50 mL ethanol (from the 95% stuff) you need (50/95)*100 = 52.63 mL. (You can see that 52.63 mL (of 95% stuff) x 0.95 = 50 mL of PURE ethanol. Then add water to 100 mL total volume. For 70%, you need (70/95(*100 = approximately 75 mL.

## Similar Questions

1. ### Chemistry

What volume (mL) of the solute ethanol should be combines with 2.44L of the solvent H2O to prepare a solution that is 8.03m ethanol?
2. ### chemistry

What is the mass/vol % ethanol in an ethanol-water solution with density of 0.875 g/ml and containing 65.0% ethanol by volume?
3. ### Chemistry- urgent help needed

How do I prepare 40% v/v from 95% ethanol?
4. ### Chemistry -repost thank you in advance

I have a bottle of 95% ethanol purchased from the manufacturer. Normally, when it is not stated, does it mean 95% w/w ethanol?
5. ### Chemistry

When doing a simple distillation of ethanol-water, is the vapor pure ethanol or does it also contain water?
6. ### Chemistry

How to prepare 1L of 96% v/v ethanol from 99% v/v ethanol?
7. ### Chemistry-help

Posted by anne on Wednesday, February 15, 2012 at 3:20pm. How to prepare 1L of 96% v/v ethanol from 99% v/v ethanol?
8. ### Chemistry

What mass of water must be used to dissolve 20.0 grams of ethanol, C2H5OH, to prepare a 0.0500 molal solution of ethanol?
9. ### Chemistry #11

A solution of ethanol (C2H5OH) is prepared by dissolving 35.0 ml of ethanol in enough water to make 120.0 ml of solution. What is the molarity of the ethanol in this solution?
10. ### chemistry

When 25 mL of C2H5OH (density 0.80 g.cm-3) is dissolved in water to prepare a 250 mL solution, the density of the solution was found to be 0.950 g.cm-3. Calculate a. Molarity of pure ethanol; b. Molarity of ethanol in the final solution; …

More Similar Questions