I've always thought that an understanding of dilution factors can make a Chemistry student's life a whole lot easier, but at the same time, always avoided teaching it (or indeed making reference to it) because of the muddle students make of it (thinking that every calculation involving a solution can be dealt with using dilution factor "formulae") .... and even worse, biology students always seem to have a desire to just "add volumes" together (even if the volumes are not additive!).
The new dilution factor resources are available to AUS-e-TUTE Members in the Members Only area (and teachers will find a worksheet wizard in the Teachers Area).
Not a member?
You can find out about AUS-e-TUTE Membership at http://www.ausetute.com.au/membership.html
and you can join AUS-e-TUTE at http://www.ausetute.com.au/register.html
There is a free-to-view tutorial currently available at http://ausetute.com.au/dfactor.html