weight loss cardiff answers:

The density of diethyl ether at 20 deg C is 0.7135 g/mL. (Your value of 255 – unknown units – is wrong).
2.5 L x 1000 mL/L x 0.7135 g/mL x 1000 mg/g = 1,784,000 mg
1,784,000 mg / 486 m^3 = 3670 mg/m^3
3670 mg/m^3 exceeds 1520 mg/m^3

weight loss cardiff answers:

There are only london dispersion forces between the two chemicals, because hexane is nonpolar, and cannot have any other intermolecular attractions

weight loss cardiff answers:

In short, not really. The only way to effectively separate petroleum distillates from diethyl ether in starter fluid is by fractional distillation. This requires appropriate equipment and training in relevant lab procedures, can be EXTREMELY dangerous, and is outside of the skillset of most people.

Some websites and experience reports mention a “water extraction” procedure that involves shaking a mixture of distilled water and starter fluid.

The so-called “water extraction” method is simplistic and ineffective, since petroleum distillates and water are not miscible (petroleum distillates do not dissolve in water), and the distillates stay mixed with the ether, because of their common chemical nature. In fact, if the components in the water-insoluble fraction were to separate, which is highly unlikely, the density of ether would put it at the bottom, closest to the water, at the water:non-polar interface, making it very difficult to isolate. Because ether is slightly soluble in distilled water, the volume of the ether in the water-insoluble fraction may actually be reduced by repeated shaking and separating.

Ether is slightly soluble in distilled water and heptane is insoluble. Hence, if one were to try to clean up starting fluid via repeatedly shaking with distilled H2O and then separating the layers, you not only don’t end up with very good ET2O, but you are actually reducing the amount of ether that you have.