Sodium carbonate (Na2CO3) is an ionic compound. When it is dissolved in water, it dissociates into sodium ions (Na+) and carbonate ions (CO32-). However, in hexane, which is a non-polar solvent, sodium carbonate does not dissolve.
The reason for this is that hexane is a non-polar solvent, and ionic compounds like sodium carbonate are not soluble in non-polar solvents. Ionic compounds are generally soluble in polar solvents like water because the polar molecules can interact with the ions, stabilizing them and allowing them to dissolve. In contrast, non-polar solvents like hexane do not have the ability to stabilize the ions, so ionic compounds remain insoluble.
Therefore, sodium carbonate is ionic and does not dissolve in hexane due to the lack of polarity in the solvent.