Final answer:
Without specific solubility data, the exact amount of additional solute that can be dissolved by increasing the temperature from 20℃ to 30℃ cannot be determined. However, generally, solubility increases with temperature for many solutes, and a solubility curve is needed for precise calculations.
Step-by-step explanation:
The question is how much more solute can be dissolved in a saturated solution of an unknown substance if the temperature is raised from 20℃ to 30℃. Without specific solubility data for the compound at these temperatures, it's not possible to give a precise answer. However, in general, solubility often increases with temperature for most solid solutes in liquid solvents. This means that an increase in temperature usually allows more solute to dissolve in the solvent. If we had a solubility curve for the substance in question, we could use it to find out the exact increase in solubility with temperature change. This curve would show the amount of solute that can be dissolved in a set amount of water at various temperatures, thus allowing us to calculate the difference between solubility limits at 20℃ and 30℃ respectively.