You need more information to determine the mass of salt. Here's why:

* Density is key: The mass of a substance depends on its density. Density is the amount of mass per unit volume.

* Salt's Density: The density of salt is approximately 2.16 g/cm³. This means that 1 cubic centimeter of salt has a mass of 2.16 grams.

To calculate the mass of salt, you need to know the volume in the correct units:

* If the volume is 4 cubic centimeters (cm³):

* Mass = Density x Volume

* Mass = 2.16 g/cm³ x 4 cm³

* Mass = 8.64 grams

* If the volume is in a different unit (like liters, milliliters, etc.): You'll need to convert the volume to cubic centimeters before applying the density formula.

Let me know the volume unit, and I can help you calculate the mass of salt.