Introduction to Combustion and Fire Case Study Example | Topics and Well Written Essays - 4250 words

Introduction to Combustion and Fire - Case Study Example For example, when chlorofluorocarbons (CFCs) are exposed to high energy sun rays, chlorine and bromine atoms are released. These chlorine/bromine atoms act as catalysts in the breaking up of ozone molecules. Free radicals are atoms or molecules possessing one or more unpaired electrons. Free radicals are formed as intermediaries of reactions. One of the most common free radicals is the hydroxyl free radical (HO∙). Ions, free atoms, and free radicals are reaction intermediaries. While ions are charged species, free radicals are groups containing unpaired electrons, and free atoms are single atoms without charge. Ions can exist in a stable equilibrium, but free atoms and free radicals are highly unstable and react with other atoms or molecules soon after formation. During bond formation, an electron from 2s orbital is moved to 2pz orbital. This process requires a small amount of energy as the energy gap between 2s and 2p orbitals are less. So the new electronic structure is 1s22s12px12py12pz1 Pentane has a molar mass of 72.15 gmol-1. For 1 mole of pentane, mass is 72.15 g. As calculates earlier, at temperature 298.15K and pressure 1.013Ãâ€"105 Pa, the volume of 1 mol of pentane is 2.447Ãâ€"10-2 m3. A reaction where the products are in the most stable state is known as a complete chemical reaction. In the fire, a complete chemical reaction with no fuel and oxygen left is known as a stoichiometric reaction. The reaction mixtures in such a state are stoichiometric mixtures. The stoichiometric oxygen to fuel mass ratio r is determined from the equation. The equivalence ratio () which describes the state of the reactant mixture, is defined as (Quintere, 2006): Concentration is a measure of the packaging of particles per unit volume and its unit is moles per dm3 or moldm-3. A mole is a unit to measure the amount of substance. One mole of a substance contains 6.023Ãâ€"1023 atoms, molecules, or ions.