Solution, a chemical mixture

Most of the chemical processes happen is solution. Life is a sum of a series of complex processes occurring in solution. A solution is a homogeneous mixture, so that it has uniform properties and composition.

It consists of solvent, a majority of a solution (for example water), and one or more solutes (for example sugar) that dissolve into solvent. Solutions are random mixtures of atomic, ions, or molecular sizes.

Components never separate spontaneously, even if the density of a solution differs. They distribute themselves in a random manner, but efficiently. Diffusion time duration depends on substances. Diffusion in a liquid is slower that that of gases.

Solutions can be in form of liquid, gas, solid form or its combination. The Atmosphere is, for example, a solution of solvent nitrogen dissolves other gases such as oxygen, carbon dioxide, water vapor, and neon.

We distinguish organic and inorganic solutions. Organic solvent is, for instance, alcohol. Inorganic solvents are commonly used in laboratory, industry or as home chemicals.

Conditions that affect solubility is 

• Pressure

It has an effect mostly on gaseous solutes. For example, when we remove a cap from soda water bottle and dioxide gas leaves a water. At any specified temperature, the extent to which a gas dissolves in a liquid is directly dependent upon the pressure of the gas.

• Temperature

Temperature has an effect, because the solubility of a gas in a liquid solvent decreases with increasing temperature. Most of the time, solubility of solids in liquids increases with an increase in temperature.

• Nature of components

As a example, let's consider a crystal. It consists of regular arrangement of atoms, ions and molecules. The forces that hold crystal together are electrostatic. For a ionic crystal to dissolve in water, the water has to shield the negative and positive charges of ions. The solubility of ions depends on electrostatic forces that hold the crystal together.

Properties of solutions

Pure liquids have properties of their physical properties such as melting point, vapor pressure and osmosis. By adding solute into solution, there characteristics change. The changes observed in there properties varying from the pure solvent to a solution depends upon the number of solute molecules. These properties are called colligative properties.

• Melting/boiling points

Solutions exhibit higher boiling points and lower melting points than the parent solvent. Such as antifreeze solutions for cars.

• Vapor pressure

Vapor pressure of a water is 100%. This magnitude is equal to the atmospheric pressure allowing bubbles of gaseous water to escape from the liquid state. The vapor pressure of a solution is less than that of a solvent. The boiling point of water increases with the addition of salt, because salt has a lower vapor pressure that pure water. The boiling point elevation and the vapor pressure depression are related.

• Osmosis

Osmosis is responsible for the transfer of molecules through cell walls in biological processes. Semis permeable membrane is a material that allows molecules of one kind to pass through the membrane but prevent other ones to pass. Usually membranes permit to pass solvent and prevent solute molecules. It is important process in biology and medicine. So osmosis is something as a selection of specific molecules that can be used and those that should stay, for example to not make the cells dehydrated.

Maybe we can get inspired by nature and solve the water pollution problem by Osmosis. Osmosis can separate solute from solvent without energy input. The main flaw of distillation and purification processes (look at Water, the universal solvent post) is high requirement of energy. Maybe something we can look at.