Physical change mixture components separated

The atoms within a compound are chemically bonded together and do not come apart through the course of a physical change. The components of a mixture, however, may be separated from each other by physical means. 

Matter can be either a pure substance or a mixture. Pure substances cannot be further broken down into simpler components through physical processes and can be either elements (one type of atom) or compounds (more than one type of atom). Mixtures can be homogeneous (aka. solutions) or heterogeneous. Heterogeneous mixtures exhibit phase boundaries, or sharp demarcations where the chemical and/or physical properties of the sample change. Mixtures are separable into pure substances through physical processes. 

Figure 2.ID depicts a mixture, a group of two or more substances (elements and/or compounds) that are physically intermingled. In contrast to a compound, the components of a mixture can vary in their parts by mass. Because its composition is not fixed, a mixture is not a substance. A mixture of the two compounds sodium chloride and water, for example, can have many different parts by mass of salt to water. At the atomic scale, a mixture is merely a group of the individual units that make up its component elements and/or compounds. Therefore, a mixture retains many of the properties of its components. Saltwater, for instance, is colorless like water and tastes salty like sodium chloride. Unlike compounds, mixtures can be separated into their components by physical changes chemical changes are not needed. For example, the water in saltwater can be boiled off, a physical process that leaves behind the sodium chloride.

Describe the process of distillation depided in Figure 2.15. Does the separation of the components of a mixture by distillation represent a chemical or a physical change ... 

UnUke compounds, mixtures can be separated into their components by physical changes chemical changes are not needed. For example, the water in saltwater can be boiled off, a physical process that leaves behind solid sodium chloride. The following sample problem will help differentiate these types of matter. 

A mixture consists of two or more substances mixed together, not chemically combined. The components retain their individual properties, can be present in any proportion, and can be separated by physical changes. 

In this chapter we shall consider applications of stability theory to critical phenomena of liquid-vapor transitions and separation of binary mixtures. When the applied pressure and temperature are altered, systems can become unstable, causing their physical state to transform into another distinct state. For example, when the temperature of a two-component liquid mixture (such as hexane and nitrobenzene) changes, the mixture may become unstable to changes in the composition the mixture then separates into two phases, each rich in one of the components. In Chapters 18 and 19 we shall see that in far-from-equilibrium systems, loss of stability can lead to a wide variety of complex nonequilibrium states. We shall also look at how a system that can undergo internal transformations responds to a rapid change in temperature. This leads us to the concept of configurational heat capacity. 

Describe how distillation and filtration rely on physical changes and properties to separate components of mixtures. 

The simplest way to produce a material in which the chemical composition of the material has been changed would be to blend two different types of polymer together. The polymer formed from a single monomer is termed a homopolymer. Whether or not blending results in a change or a superposition of the physical properties of the two component materials depends on whether or not they are thermodynamically compatible. If the polymers have similar structures then they may form a homogeneous mixture in the melt, and the physical properties which result are a blend of those of the component polymers. If, however, they do not mix then the resultant material is a mixture of separate phases, each of which will exhibit its own properties. 

Physical separation techniques separate a mixture such as a crude oil without changing the chemical characteristics of the components. The... 

The essential difference between physical and chemical interactions is that in the former the interacting molecules are not chemically modified in any way. Hydrogen bonding may change, but there are no chemical changes that create a different molecule. However, this does not mean that the different components of the interaction can be easily separated the resultant mixture may be so intimate that separation is not possible. For example, silicified microcrystalline cellulose after processing cannot be separated entirely into its two separate components (fumed silica and microcrystalline cellulose). But on examination, using a number of vibrational spectroscopic methods, it was shown to be an intimate physical mixture and not a new chemical entity (8). 

The identification of the chemical forms of an element has become an important and challenging research area in environmental and biomedical studies. Two complementary techniques are necessary for trace element speciation. One provides an efficient and reliable separation procedure, and the other provides adequate detection and quantitation [4]. In its various analytical manifestations, chromatography is a powerful tool for the separation of a vast variety of chemical species. Some popular chromatographic detectors, such flame ionization (FID) and thermal conductivity (TCD) detectors are bulk-property detectors, responding to changes produced by eluates in a characteristic mobile-phase physical property [5]. These detectors are effectively universal, but they provide little specific information about the nature of the separated chemical species. Atomic spectroscopy offers the possibility of selectively detecting a wide rang of metals and nonmetals. The use of detectors responsive only to selected elements in a multicomponent mixture drastically reduces the constraints placed on the separation step, as only those components in the mixture which contain the element of interest will be detected... 

One characteristic of a mixture is that it can be separated into its components by physical processes. The word physical means that the process does not change the chemical identity of a substance. How could you separate a sand/sugar mixture into pure sand and pure sucrose The simplest physical means would be to look at it with a microscope and separate the bits of sugar and sand with tweezers. You are right in thinking that there must be an easier way. 

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