attractive forces between ion and water = ion-dipole
∆Hhydration = heat released when 1 mole of gaseous ions
dissolves in water
∆Hsolute = - ∆Hlatic
Heat of Hydration The term ‘heat of hydration’ is applied to the heat generated by the chemical reactions, which occur in setting concrete between the water and cement. The heat causes the concrete first to expand and then to shrink as it cools. If there is a temperature gradient across the concrete or the concrete is otherwise restrained, cracking may occur. The two factors, which are most likely to cause excessive generation of heat, are very large pours and high cement contents. Some specifications set amaximum cement contentin order to limit the generation of heat.
This is a set up for Decomposition of Hydrogen Peroxide. H2O2. The yellow hexagon shape you see is an inverted graduated cylinder. It is filled with water. You may have played with a similar set up as a kid in a bath tub. If you invert a container in water, it does not lose any water in the cylinder. A syringe is filled with 3 ml of KI (Potassium Iodine. The tube is then inserted into the cylinder. The Erlenmeyer flask has a rubber stopper so it is air tight. One the syringe is injected into the flask that is filled with air, the reaction cause a release of gas which then travels through the tube and into the graduated cylinder. The gas displaces the water from the cylinder into the container.