Matter can be divided in two categories. It consists of single types of particles which are same in their chemical nature. Mixture consists of two or more particles.
Solubility and Solvation The ability of one compound to dissolve in another compound is called solubility. When a liquid can completely dissolve in another liquid the two liquids are miscible. Two substances that can never mix to form a solution are called immiscible.
All solutions have a positive entropy of mixing. The interactions between different molecules or ions may be energetically favored or not. If interactions are unfavorable, then the free energy decreases with increasing solute concentration. At some point the energy loss outweighs the entropy gain, and no more solute particles can be dissolved; the solution is said to be saturated.
However, the point at which a solution can become saturated can change significantly with different environmental factors, such as temperaturepressureand contamination.
For some solute-solvent combinations a supersaturated solution can be prepared by raising the solubility for example by increasing the temperature to dissolve more solute, and then lowering it for example by cooling.
Usually, the greater the temperature of the solvent, the more of a given solid solute it can dissolve. However, most gases and some compounds exhibit solubilities that decrease with increased temperature. Such behavior is a result of an exothermic enthalpy of solution.
Some surfactants exhibit this behaviour. The solubility of liquids in liquids is generally less temperature-sensitive than that of solids or gases. Properties The physical properties of compounds such as melting point and boiling point change when other compounds are added.
Together they are called colligative properties. There are several ways to quantify the amount of one compound dissolved in the other compounds collectively called concentration.
Examples include molarityvolume fractionand mole fraction. The properties of ideal solutions can be calculated by the linear combination of the properties of its components. In the practice of chemistry and biochemistry, most solvents are molecular liquids.
They can be classified into polar and non-polaraccording to whether their molecules possess a permanent electric dipole moment. Another distinction is whether their molecules can form hydrogen bonds protic and aprotic solvents. Waterthe most commonly used solvent, is both polar and sustains hydrogen bonds.
Water is a good solvent because the molecules are polar and capable of forming hydrogen bonds 1. Salts dissolve in polar solvents, forming positive and negative ions that are attracted to the negative and positive ends of the solvent molecule, respectively.
If the solvent is water, hydration occurs when the charged solute ions become surrounded by water molecules. A standard example is aqueous saltwater. Such solutions are called electrolytes.
Whenever salt dissolves in water ion association has to be taken into account.
Polar solutes dissolve in polar solvents, forming polar bonds or hydrogen bonds.A colloid contains particles of solid or liquid, or, bubbles of gas while these particles are suspended within a solid, liquid or gas, with the exception of gas colloid bubbles being suspended in a .
Ian Morrison© Surfactant science and technology Dispersions in liquids: suspensions, emulsions, and foams ACS National Meeting April 9 – 10, Study Material and Notes of Ch 2 Is Matter Around us Pure Class 9th Science. Colloids are mixtures whose particles are larger than the size of a molecule but smaller than particles that can be seen with the naked eye.
Product Reports. Skip to the Lab Analysis Summary. There are three distinctly different types of silver that are labeled and sold on the market as “colloidal silver”; they are ionic silver, silver protein, and true colloidal silver.
Consumers seeking true colloidal silver are often at a disadvantage because each of these products represents themselves as colloidal silver. Colloids are mixtures whose particles are larger than the size of a molecule but smaller than particles that can be seen with the naked eye.