ENTHALPYWhat is enthalpy?Enthalpy is the amount of contained heat used or released in a persistent pressure system. Enthalpy is typically articulated as the change in enthalpy. The enthalpy variation is linked to a variation in internal energy (U) and a variation 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 gives off heat, it is exothermic. In this case, the enthalpy change is negative, as the reaction goes from high energy to low energy due to the loss of thermal energy to the surroundings. If energy flows from the surroundings and heat is absorbed, it is endothermic. The change is positive since the system is gaining energy in the form of heat. Bond Formation 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 accurate/exact bond enthalpy of a particular chemical depends on the molecular environment in which the bond exists. Molar bond enthalpy is the energy needed 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 formation is a 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 following reaction shown...... middle of paper ...... n-Caution with any glass objects Disposal of residues -Extra liquidsColorimetryColorimetry is the process of determining the concentration of a substance by 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 knowledge In chemistry, colorimetry is widely used. They use it for things like color painting, food production, 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 the colored solute. To use a colorimeter it is necessary to make several types of solutions, including a regulator or orientation of the identified concentration.