Question

Now supposed you wanted to dilute this 0.4 M NaCl solution by a 1:10 dilution - how would you do this?

Answer 1

Well, take a `10*mL` aliquot....

Explanation:

...by means of a pipette...transfer the volume to a volumetric flask of `100*mL` volume...and make the flask up to volume...

And the new concentration is...`(0.4*mol*L^-1xx10^-2*L)/(100*mLxx10^-3*L*mL^-1)=0.040*mol*L^-1` as required...