Solutions
In chemistry, a solution is a homogeneous mixture of two or more substances. The substances that are dissolved are called solutes. The substance the solutes are dissolved in is called the solvent. An example from everyday experience is a solid like salt or sugar (which are crystalline solids), dissolved in a liquid (like water). Gases can dissolve in liquids. An example is carbon dioxide or oxygen in water. Liquids may dissolve in other liquids and gases in other gases.
The amount of solute added to the solvent determines the concentration of the solution. The solution with the large amount of solute is called a concentrated solution; the solution with less solute is called a dilute solution.
Examples of solid solutions are alloys and some minerals. For example, brass is an alloy of copper and zinc.
An aqueous solution is one that contains water as the solvent. An unsaturated solution has less solute than it can dissolve, while a saturated solution contains the maximum amount of solute it can hold. A supersaturated solution holds more solute than is typically possible under normal conditions.
Written for younger readers
Solutions, in simpler words
This version comes from Wikijunior, a set of books written for children aged 8 to 11. It is shorter and uses plainer language than the article above.
From Wikijunior: The Elements
=Solutions=
Before we dive into solutions, let’s separate solutions from other types of mixtures. Solutions are groups of molecules that are mixed up in a completely even distribution. Not the easiest way to say it. Scientists say that solutions are homogenous systems. Other types of mixtures can have a little higher concentration on one side of the liquid when compared to the other side. Solutions have an even concentration throughout the system. An example: Sugar in water vs. Sand in water. Sugar dissolves and is spread throughout the glass of water. The sand sinks to the bottom. The sugar-water could be considered a solution. The sand-water is a mixture. No matter how hard you stir, the sand will not disappear into the water the way the sugar will.
Pretty much. Solutions can be solids dissolved in liquids. They could also be gases dissolved in liquids (such as carbonated water). There can also be gases in other gases and liquids in liquids. If you mix things up and they stay at an even distribution, it is a solution. You probably won’t find people making solid-solid solutions in front of you. They start off as solid/gas/liquid-liquid solutions and then harden at room temperature. Alloys with all types of metals are good examples of a solid solution at room temperature. A simple solution is basically two substances that are combined, called the solute and the solvent. The solute is the substance to be dissolved (sugar). The solvent is the one doing the dissolving (water). As a rule of thumb, there is usually more solvent than solute.
So what happens? How do you make that solution? Mix the two substances and stir. It’s that simple. Science breaks it into three steps. When you read the steps, remember… Solute=Sugar, Solvent=Water, System=Glass.
The solute is placed in the solvent and the concentrated solute slowly breaks into pieces.
The molecules of the solvent begin to move out of the way and they make room for the molecules of the solute. Example: The water has to make room for the sugar molecules.
The solute and solvent interact with each other until the concentration of the two substances is equal throughout the system. The concentration of sugar in the water would be the same from a sample at the top, bottom, or middle of the glass.
Sure. All sorts of things can change the concentrations of substances in solution. Scientists use the word solubility. Solubility is the ability of the solvent (water) to dissolve the solute (sugar). You may have already seen the effect of temperature in your classes. Usually when you heat up a solvent, it can dissolve more solid materials (sugar) and less gas (carbon dioxide). Next on the list of factors is pressure. When you increase the surrounding pressure, you can usually dissolve more gases in the liquid. Think about your soda can. They are able to keep the fizz inside because the contents of the can are under higher pressure. Last is the structure of the substances. Some things dissolve easier in one kind of substance than another. Sugar dissolves easily in water; oil does not. Water has a low solubility when it comes to oil.
Where this page comes from
The article above is adapted from “Solutions” on Simple English Wikipedia, by its contributors. We removed reference markers, navigation boxes and tables, expanded measurement templates into readable numbers, and kept the prose otherwise intact. The simpler version is adapted from Wikijunior on Wikibooks.
Both sources are published under CC BY-SA 4.0, so this page is published under the same licence. You may share and adapt it, including commercially, as long as you credit the original and keep the same licence.
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