500
You have 53 mL of a solution in a cup. You know the solvent is water, but you don't know what the solute is. How can you find out?
Pour some of the solution into an evaporation dish and wait for the water to evaporate. Crystals of the solute will be left. You can identify the solute by the properties of the crystals (for example, salt crystals would be square, with an X in the middle).