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

1 Answer
Nov 2, 2016

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.