Answer:
Compare the various physical properties of the substance.
Step-by-step explanation:
One way is to compare the various physical properties of the substance. Let's take a look at those:
Identify the physical identity of each substance. That is, it the substance solid, or powder, or granulated (in small granules)
Next, the color of the substance will also help as a physical property. For example, is the substance bright, shiny, dull in color, etc.
Another property of the test can be the electrical conductance. For instance, does the substance conduct electricity or not.
Finally, test if the substance dissolves in a solvent, say water in this case. If it dissolves, it is likely to be a soluble salt. If not, then it is likely to be an insoluble salt.