Question

What is the best way to compare a concentrated solution to a dilute solution, given the same volume of solution?

Answer 1

One of the physical ways is that the concentrated one will be more colourful than the dilute one.

Answer 2

if the solutions are colored, then as @hoslos suggests it can be done by color. If the solutions are not colored, you can use density, and if the solutions are ionic you can use conductivity

Answer 3

To add what JFraser said, in conductivity, place wires in the solution and make sure you have as ammeter or voltmeter to measure the solution that will produce the greatest magnitude.
Conclusively, the best ways would be Conductivity and Physical appreciation of colour intensity.
Other than that, @JFraser , they asked for the best way. Which one of these two could we rely on?

Answer 4

color only works if the solutions are colored. I'd go with density

Answer 5

Yes, between density and conductivity.

Answer 6

conductivity will only work if the solutions are ionic. We don't know that based on this information.

density is uniformly applicable to all types of solutions, whether colored, transparent, ionic, or covalent