The sign of change of heat of solution is positive
Explanation:
The dissolution of AgNO3 in water is represented by the equation;
AgNO3(s) --------> Ag^+(aq) + NO3^-(aq)
We can see from the question that as the temperature was increased from 10° to 20°C the solubility of the solute increased from 170g to 222g per 100g of H2O.
This implies that the solubility of the solute increases with increase in temperature.
If a reaction moves in the forward direction when the temperature is increased, then the reaction is endothermic. If the reaction is endothermic, the sign of change of heat of solution is positive.
