Final answer:
The solubility of salt at 60 degrees Celsius is 5 grams.
Step-by-step explanation:
The solubility of a substance is the amount of that substance that is required to form a saturated solution in a given amount of solvent at a specified temperature. Solubility is often measured as the grams of solute per 100 g of solvent. The solubility of sodium chloride in water is 36.0 g per 100 g water at 20°C. The temperature must be specified because solubility varies with temperature.
Given that 2 grams of salt remain as a residue when 7 grams of a saturated solution prepared at 60 degrees Celsius is dried, we can determine the solubility of salt at 60 degrees Celsius. This means that 5 grams of salt dissolved in the saturated solution (7 g - 2 g = 5 g). Therefore, the solubility of salt at 60 degrees Celsius is 5 grams.