faster interaction between cleaning solvent molecules and the dissolved substances. Agitation also separates particles by pro-viding the initial momentum for the bodies of charged particles to separate and rearrange themselves according to their electrostatic charges. What Is Cleaning Chemistry? Chemistry — or the “science of substance” — examines the matterʼs structure, the substanceʼs properties and reactions that change them into other substances. Chemical action makes separating mat-ter during cleaning effective. Matter consists of atoms or small parti-cles while elements contain similar atoms. Compounds form when atoms of same or different elements bind together in a defi-nite proportion. A molecule is a compoundʼs smallest particle that exists and exhibits that com-poundʼs properties. Compounds are a pure substance decomposed by chemical change. Atoms continuously cycle or rearrange themselves into different compounds and substances and release or absorb energy. Polluting substances differ in their dis-solvability in various solutions. For example, oil does not dissolve in water, only in another organic solution, such as naphtha. Sodium chloride (table salt) dissolves in water but not gasoline. In cleaning it is important to understand how matter dissolves and becomes sus-pended before being removed. Most chemical action in cleaning occurs when polluting substances dissolve in solutions. Solutions are a homogeneous mixture or have the same chemical structure. Mixtures can consist of air or water. Cleaning solutions often combine water containing soaps, detergents or an organic solvent in liquid or gas form. Substances or pollutants are soluble if they cannot be dissolved. A cleaning solution is a solvent if its chemical nature is maintained while dis-solving the substance or pollutant. Upon dissolution molecules or ions are distributed and occupy the positions nor-mally held by the dissolving solutionʼs molecules. A liquidʼs molecules are closely packed. Compared to solutions in air, they inter-act strongly with neighboring molecules. These molecules separate and interface weakly in gaseous solutions. How easily a dissolved substanceʼs mol-ecule is replaced by a dissolving solution depends on the attraction forces. Benzene dissolves in carbon tetrachlo-ride solutions. Each substanceʼs attraction forces are nearly equal. The benzene molecules easily can replace those of the carbon tetrachloride solution. Two completely soluble substances are miscible. This same chemical relationship explains www.cmmonline.com 23
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