# Question #d5ccd

##### 2 Answers

So you take the concentration of whatever you want to dilute, say of 1ml volume, then you add 80ml of water.

So then you have a 1:80 dilution.

You can also then work out the concentration of your final dilution by putting in the values into the equation I gave.

Hope I helped :)

The answer Rogan wrote is correct, but his example is a little off.

Adding **80 mL** of water to **1 mL** of stock solution will produce a **1:81** dilution, *not* a **1:80** one.

The ratio between the final volume of the solution, the one you get *after* diluting the initial sample, and the initial volume of the sample will give you the *dilution factor*

So,

If you've got a **1-mL** sample, and the dilution factor is **1:80**, you'd get

However, this volume **includes** the volume of the aliquot, the original sample you wanted to dilute, which means that the **80-mL** final volume will include **1 mL** of sample, the rest being the volume of the diluent

So, to make a **1:80** dilution for a **1-mL** sample, you *add enough water* to get the final volume to **80 mL** **79 mL** of water to the **1-mL** sample.

If you add **80 mL** of water, you'll get a dilution of **1:81**

Read more about the dilution factor here:

http://socratic.org/questions/how-do-you-calculate-dilution-factor?source=search