Substances homogeneous mixtures

Design a concept map that summarizes the relationships among matter, elements, mixtures, compounds, pure substances, homogeneous mixtures, and heterogeneous mixtures. 

An important purpose of agitation or mixing is to bring a number of materials together in a physically homogeneous mixture. Two or more fluids are either blended or dispersed as emulsions fluids and finely divided solids are dispersed as suspensions, gases dispersed as fluids, or soluble substances dissolved. Mixing of process fluids is reviewed in Chapter 7. 

A homogeneous mixture of two or more components, whether solid, liquid, or gaseous, is called a solution. Solutions have variable composition while pure substances do not. That is, the relative amounts of the various components in a solution can vary. Thus, air, salt water, and sixteen carat gold are each solutions. The gemstone, ruby, is also a solution since it consists of the mineral corundum (AI2O3) with some of the aluminum replaced by chromium to give the crystal its characteristic color. Since the amount of chromium present can be varied, ruby is a solution. 

FIGURE G.3 Solutions are homogeneous mixtures in which one substance, the solvent (here water), is usually in large excess. A dissolved substance is called a solute. 

Example butter, an emulsion of water in butterfat. solid solution A solid homogeneous mixture of two or more substances. 

Decide whether each of the following molecular pictures represents a pure substance, a homogeneous mixture, or a heterogeneous mixture. Tell whether the sample Is a solid, a liquid, or a gas. 

A solution is a homogeneous mixture of two or more substances. As described in Chapter 3, a solution contains a solvent and one or more solutes. The solvent determines the state of the solution, and normally the solvent is the component present in the greatest quantity. The most common solutions are liquids with water as solvent, but solutions exist in all three states of matter. The atmosphere of our planet, air, is a gaseous solution with molecular nitrogen as the solvent. Steel is a solid solution containing solutes such as chromium and carbon that add strength to the solvent, iron. 

The designation (aq) indicates a water solution. (Three other chemical states and their formula notations include liquid [1], solid [s], and gas [g].) The substance is in a solution, which is defined as a homogenous mixture of two or more substances. Homogenous means that the solution has a uniform chemical makeup. In other words, if you took samples of a solution from two different areas of its container, the two samples would look the same and have the same chemical composition, as would, say, two spoon-0 fills of vanilla ice cream scooped from different parts of the same... 

The concept of substance activity was derived by Gilbert N. Lewis in 1907 from the laws of equilibrium thermodynamics and is described in detail in the text entitled Thermodynamics and the Free Energy of Chemical Substances by Lewis and Randell (1923). In a homogeneous mixture, each component has a chemical potential (jjl), which describes how much the free energy changes per mole of substance added to the system. The chemical potential of water (pw) in a solution is given by... 

A solution is a homogeneous mixture composed of solvent and one or more solutes. The solvent is normally the substance present in the greatest amount. The solute is the substance that is present in the smaller amount. If water is the solvent, it is an aqueous solution. You may have more than one solute in a solution. 

Emulsifier not normally used as characteristic ingredients of food Substance which makes it possible to form or maintain a homogenous mixture of two or more immiscible phases such as oil and water in a foodstuff... 

We discuss solutions further in the chapter on solutions and colligative properties, but solution stoichiometry is so common on the AP exam that we will discuss it here briefly also. Solutions are homogeneous mixtures composed of a solute (substance present in smaller amount) and a solvent (substance present in larger amount). If sodium chloride is dissolved in water, the NaCl is the solute and the water the solvent. 

Summary A solution is a homogeneous mixture composed of a solvent and one or more solutes. The solvent is the substance that acts as the dissolving medium and is normally present in the greatest amount. Commonly the solvent is a liquid, but it doesn t have to be. Our atmosphere is a solution with nitrogen as the solvent it is the gas present in the largest amount (79%). Many times you will be dealing with a solution in which water is the solvent, an aqueous solution. The solute is the substance that the solvent dissolves and is normally present in the smaller amount. You may have more than one solute in a solution. For example, if you dissolved table salt (sodium chloride) and table sugar (sucrose) in water, you would have one solvent (water) and two solutes (sodium chloride and sucrose). 

Colloid chemistry investigates substance mixtures. These substance mixtures can be heterogenous, such as emulsions (in which tiny droplets of one liquid are dispersed in another), suspensions (consisting of a fine dispersion of solid particles in a liquid volume phase), and aerosols (in which liquid droplets are dispersed in the gas phase). However, there are also homogenous mixtures in which the solute is present in larger, supermolecular aggregates. These homogenous mixtures include micellar solutions and liquid crystalline... 

In closing this section, remember that Aristotle rejected the concept of atoms. Aristotle could not accept the idea of a void space and believed that nature abhors a vacuum. Furthermore, Aristotle did not consider internal structure. Substances contained their qualities and elements as a homogenous mixture. An Aristotelian would explain the reaction of hydrogen gas and oxygen gas to produce liquid water as... 

The attractions of a drying agent which forms a homogeneous mixture with the substance to be dried, e.g. triethyl aluminium or dibutyl magnesium with hydrocarbons and some other compounds, are obvious the former can be used with methyl methacrylate, the latter with styrene and with dienes. However, it is questionable whether the difficulty of separating the dried compound completely from unused drying agent and the fire-hazard associated with many metal alkyls make the effort worth while, except in some special cases. 

A solution is a homogeneous mixture of two or more substances. A minor species in a solution is called solute and the major species is the solvent. In this book, most discussions concern aqueous solutions, in which the solvent is water. Concentration states how much solute is contained in a given volume or mass of solution or solvent. 

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