Question

If 200 mL of a 2.50 M `NaOH` solution is diluted to 500 mL, what is the new concentration of NaOH?

Answer 1

The new concentration is `1.00*mol*L^-1`.

Explanation:

`"Concentration"` `=` `"Moles of solute"/"Volume of solution"`

We use this relationship to get the initial number of moles, by taking the product,`"concentration"xx"volume"`, and then dividing this molar quantity by the new volume, which we get by simply adding the 2 given volumes.

And thus, `(200xx10^-3cancelLxx2.50*mol*L^-1)/(500xx10^-3cancelL)`

And we get an answer with units `mol*L^-1` as we require.