Marina Horta Enthalpy of Hydration Lab October 29/09
Abstract; The purpose of this experiment was to calculate the enthalpy of hydration for Magnesium Sulfate. Using the enthalpy of dissolution and Hess’s Law the results of this lab were calculated to be -17197.18 kj mol-1. Using the graphs as a reference the final calculation can be determined to be on average correct.
Introduction; The formation of a solution involves the interaction of solute with solvent molecules. When a solute is dissolved there are three energy process involved; The first is the separation of the solvent molecules which requires energy and so is an endothermic reaction, the second is also and endothermic reaction, the separation of the solute ions or molecules, and last is the attractive force between the solute molecules and the solvent, releasing energy ,exothermic. Water is commonly used as a solvent; this dissolving process is called hydration. The heat involved in a chemical reaction, at constant pressure is referred to as enthalpy and usually refers to the“…amount of energy released for one mole of the ion dissolved in a large amount of water forming an infinite dilute solution in the process.”1 Enthalpy change in a solution is shown by the equation where the overall positive or negative energy depends on the values of each trial.
