Question

How can we make 10 fold dilution when we only have 0.5 ml of stock solution?

Answer 1

Here's how you can do that.

Explanation:

The idea here is that in a `10`-fold dilution, the volume of the diluted solution is `10` times higher than the volume of the stock solution.

This is equivalent to saying that the concentration of the stock solution is `10` times lower than the concentration of the diluted solution.

In other words, you're performing a `1:10` dilution, i.e. you're diluting the stock solution by a factor fo `10`.

`"DF" = V_"diluted"/V_"stock"" "->` the dilution factor

In your case, you have

`V_"diluted"/V_"stock" = 10 implies V_"diluted" = 10 * V_"stock"`

This means that the volume of the diluted solution must be equal to

`V_"diluted" = 10 * "0.5 mL" = "5 mL"`

So depending on the nature of the substance that you're diluting, you can add enough water to the stock solution to get the total volume to `"5 mL"`.

If you're dealing with a strong acid, you would add the stock solution to enough water to get the total volume of the solution to `"5 mL"`, preferably to cold water in multiple steps while stirring properly in between steps.