a salt whose solubility increase with temperature
Dear Student,
On increasing temperature of a solution, the average kinetic energy of the molecules also increases. This increase in kinetic energy destabilizes the solid state. The increased kinetic energy of the solute molecules weakens the forces which hold them together, and thus they dissolve more easily.
Salts like Na2HAsO4 (disodium hydrogen arsenate) follow the this trend on regular heating.
Regards