ENTHALPYWhat is enthalpy?Enthalpy is the amount of heat used or released in a system at a persistent pressure. Enthalpy is generally defined as the change in enthalpy. The enthalpy change is related to a change in internal energy (U) and a change in volume (V), which is multiplied by the constant pressure of the system.04/23/14 (http://chemwiki.ucdavis edu/Physical_Chemistry/Thermodynamics/State_Functions/Enthalpy)When the reaction releases heat, it is exothermic. In this case, the enthalpy change is negative, since the reaction goes from high energy to low energy due to the loss of thermal energy to its surroundings. If the energy comes from the surrounding environment and heat is absorbed, it is endothermic. The change is positive because the system gains energy in the form of heat. Bond Creation and Bond Enthalpy Bond enthalpy is the energy required to break a chemical bond. In most cases, it is expressed in units of kJ mol-1, measured at 298 K. The most precise/exact bond enthalpy of a particular chemical depends entirely on the molecular environment in which the bond exists . The molar bond enthalpy is the energy required to break one mole of bonds between pairs of atoms in the “gas molecule”. Bond enthalpy values ​​are usually expressed in kJ mol-1 of broken bonds.04/21/14 (http://www.avogadro.co.uk/h_and_s/bondenthalpy/bondenthalpy.htm) Bond creation is an exothermic process. However, if a certain bond in a molecule is broken and then reformed, then the same amount of energy must be involved. During a chemical reaction, bonds in the reactants are broken and new bonds are created in the products. Find H for the given following reaction...... middle of paper ......n-Caution with all glass objectsRemoval of residue -Additional liquidsColorimetryColorimetry is the process of determining the concentration of a substance in measuring the relative of light. The instrument used is called a calorimeter. Colorimetry is the scientific method used to classify the colors of the spectrum. (http://www.docbrown.info/page07/appendixtrans09.htm)Basic knowledgeIn chemistry, colorimetry is used a lot. They use it for things like color painting, food manufacturing, and textiles. Colorimetry can also be used to measure light. The amount of light absorbed is called and is also measured as absorbance which is a use of the concentration of colored solute. To use a colorimeter, different types of solutions must be made, this includes a regulator or an identified concentration orientation.