Understanding Solutions
Table of Contents

Part 1: What is a Solution?Part 2: Colloids and SuspensionsPart 3: Particles in a SolutionPart 4: Effects of Solutes on SolventsPart 5: Work Cited------------------------------------------------------------What is a Solution?
A solution is a well-mixed mixture that contains a solvent and at least one solute. Solvents and solutes are what make up the solution. Solvents are part of the solution present in large amounts that dissolves into other substances. The other half of the solution, the solute, is a substance that is present in a solution in a smaller amount then solvents and it is dissolved by the solvent. For example, if the solution is air the solvent would be the oxygen in the air and the solute would be the nitrogen gas and other gases. (Prentice Hall Science explorer) Miscible is the term that is used to describe how well two substances mix with each other. The word immiscible means the complete opposite. Solubility is the same as miscible but more abstract. The solubility of a substance is the amount of the substance that will dissolve in a given amount of solvent. This also depends on temperature; increase=increase and decrease=decrease. With gas it is the opposite. Concentration is the amount of a substance, normally a solute, present in a given volume of solvent or solution. For something to be saturated it has to have a solution that contains the maximum amount of solute for a given amount of solvent at a given temperature. When something is supersaturated it means the same thing except it has the lease amount of solvents. Unsaturated is the same also but it contains less than the maximum of solvents. Endothermic solutions are solutions that absorbs heat and an exothermic solution is the solution that releases heat. (Prentice Hall Science)





Colloids and Suspensions Not all mixtures are solutions. Colloids and suspensions are mixtures that have different properties than solutions. A colloid is a mixture containing small, undissolved particles that do not settle out. Milk is considered a colloid. Solutions and colloids differ in the size of their particles and how they affect the path of light. A colloid contains larger particles than a solution. The particles are still too small to be seen easily, but are large enough to scatter a light beam. Milk has fats and proteins that form globular particles that are big enough to scatter light, but are too small to be seen. (Prentice Hall Science)Other examples are fog, a colloid that consists of water droplets in air, scatters in the headlight beams of cars. A suspension is a mixture in which particles can be seen easily separated by settling or filtration. Unlike a solution, a suspension does not have the same properties throughout. It contains visible particles that are larger than the particles in solutions or colloids. In a solution of glass cleaner, particles are uniformly distributed and too small to scatter light. (Prentice Hall Science)




Particles in a Solution

When a solution forms, particles of the solute leave each other and become surrounded particles of the solvent. There are two different types of solutes; Ionic solutes and Molecular solutes. Ionic solutes start as a substance and breaks into ions when it dissolved in water. Molecular solutes are molecules that break up into individual neutral molecules which then move away from each other over time but never break its covalent bond. The ionic compounds that are in water conduct electricity but water solutions of molecular compounds may not. If there are no ions it won’t conduct electricity.(Prentice Hall Science)
Effects of Solutes on SolventsThe freezing point of water is 0 degrees Celsius and the boiling point is 100 degrees Celsius. But solutes lower the freezing point and raise the boiling point of a solvent. When liquid water freezes, water molecules join together to form crystals of solid ice. Pure water is made only of water molecules that freeze at 0 degrees Celsius. In a slat solution, solute particles make it harder for the water molecules to form crystals. The temperature must drop lower than 0 degrees Celsius to freeze.(Prentice Hall Science) In pure water, all the molecules are water. But in a solution, some of the particles are water molecules and others are particles of solute. While in a liquid, molecules are moving close to each other. In a gas molecule, they are far apart and moving more rapidly. As the temperature of a liquid rises, the molecules gain energy and escape into the air. But the presence of a solute makes it harder for the molecules to escape, so the boiling point rises over 100 degrees Celsius.(Prentice Hall Science) Car manufacturers make use of the effects of solutes to protect the engine from overheating or freezing. The coolant in a car radiator is a solution of water and liquid called antifreeze. The mixture of the two has a higher and lower boiling and freezing point. Miller, Steve. Chemical Interactions. L. Boston, Massachusetts: Pearson, 2009. Print.