posted by Jenn .
This is for organic chem lab.
I don't understand how to calculate the relative Rf values by setting ibuprofen to 1.00. For example, my Rf value for aspirin is 0.046, so how do I calculate the Rf relative to ibuprofen (1.00)?
My experimental data for ibuprofen is 0.55 if that helps.
In essence you need
1.00 x 0.046/0.55
imagine that the solvent front has moved 10 cm then the ibuprofen spot has moved 5.5 cm and the aspirin spot has moved 0.46 cm. So if we take the ibuprofen as Rf = 1.00 then the distances travelled by other spots are relative to this. So the Rf of the aspirin is 0.46 cm/5.5 cm (relative to ibuprofen).