Question

Which statement best describes the change that is associated with the enthalpy of solution? Each step of the process is exothermic when the enthalpy of solution is negative. Each step of the process is endothermic when the enthalpy of solution is positive. Two steps of the process are exothermic, and one step is endothermic. Two steps of the process are endothermic, and one step is exothermic.

Answer 1

The correct option is this: TWO STEPS OF THE PROCESS ARE ENDOTHERMIC AND ONE STEP IS EXOTHERMIC.
The enthalpy change of solution refers to the heat change that occur when a substance is dissolved in a solvent. 
Dissolving a substance in a solvent involves three distinct steps:
1. the breaking of the inter molecular forces that is holding the substance together. This process is endothermic because it needs energy to occur, therefore its enthalphy change is greater than zero.
2. The breaking of inter molecular forces that is holding the solvent molecules together. This process is also endothermic.
3. The mixing together of the solute and the solvent. The reaction is an exothermic reaction because energy is given off as the molecules bond togeher. <span />