Formation of Solutions

Solutions are homogenous mixtures made of particles that exist as individual molecules or ions, all parts have the same properties and chemical composition. For example, a spoonful of juice taken from a jugful of juice will taste the same as any sample from any part of the same jugful of juice.

A solution consists of solute, the substance that dissolves, and solvent the substance in which the solute dissolves. A solution may have one or more solutes dissolved in a given solvent. Water is the “universal solvent”.

Bronze is a solid solution of copper and tin where tin is present in a smaller amount. Hence, tin is the solute and copper is the solvent. Solutions in which water is the solvent are called aqueous solutions. Ethanol is a common solvent in medicines.

A solution is formed when two or more substances combine in such a way that one component cannot be distinguished from others. The particles of these substances are held together by intermolecular forces. These intermolecular forces also operate between solute particles and solvent that surrounds it.

The formation of a solution involves energy change, although it may be small. Some attractive interactions are broken and others are formed during the process. Solute-solvent attractive forces and solvent-solvent attractive forces are broken and these processes are always endothermic (heat-absorbing). Solute-solvent attractive forces are formed, which is an exothermic (heat-releasing) process.

For example, table salt (NaCl) dissolves readily in water because the water molecules have a sufficient attraction for each solute particle overcome the attraction of the particles in NaCl for one another. NaCl is an ionic substance (substance composed of electrically charged atoms or groups of atom called ions). The ions separate from the crystal and combine with water molecules o form hydrated ions. These will then mix with the remaining water molecules to form an intimate homogenous mixture. Hydration involves the combination of solute molecules of water. It is specific example of the process of salvation, which is term generally used to describe the combination of solute molecules or ions with solvent molecules.

Some solutions are so common to us that we give them a unique name. A solution of water and sugar is called syrup. A solution of sodium chloride (common table salt) in water is called brine. A sterilized specific concentration (0.15 molar) of sodium chloride in water is called saline. A solution of carbon dioxide in water is called seltzer, and a solution of ammonia gas in water is called ammonia water.

Other sample is a cup of cappuccino is a combination of espresso coffee, mixed with frothed hot milk or cream and often flavored with a cinnamon.

Terms:

Soluble - substance that dissolves in another substance. Examples are salt and sugars are soluble in water.

Insoluble – substance that does not dissolve in another. Example copper and mercury do not dissolve in water.

Miscible – liquids which are soluble in each other

Immiscible – liquids that do not mix

Nature of the Solution

1. The particles of solute are the size of individual small molecules or individual small ions. One nanometer is about the maximum diameter for a solute particle.

2. The mixture does not separate on standing. In a gravity environment the solution will not come apart due to any difference in density of the materials in the solution.

3. The mixture does not separate by common fiber filter. The entire solution will pass through the filter.

4. Once it is completely mixed, the mixture is homogeneous. If you take a sample of the solution from any point in the solution, the proportions of the materials will be the same.

5. The mixture appears clear rather than cloudy. It may have some color to it, but it seems to be transparent otherwise. The mixture shows no Tyndall effect. Light is not scattered by the solution. If you shine a light into the solution, the pathway of the light through the solution is not revealed to an observer out of the pathway.

6. The solute is completely dissolved into the solvent up to a point characteristic of the solvent, solute, and temperature. At a saturation point the solvent no longer can dissolve any more of the solute. If there is a saturation point, the point is distinct and characteristic of the type of materials and temperature of the solution.

7. The solution of an ionic material into water will result in an electrolyte solution. The ions of solute will separate in water to permit the solution to carry an electric current.

8. The solution shows an increase in osmotic pressure between it and a reference solution as the amount of solute is increased.

9. The solution shows an increase in boiling point as the amount of solute is increased.

10. The solution shows a decrease in melting point as the amount of solute is increased.

11. A solution of a solid non-volatile solute in a liquid solvent shows a decrease in vapor pressure above the solution as the amount of solute is increased.

CHEMISTRY IS THE SOLUTION :D

Formation of Solutions

Solutions are homogenous mixtures made of particles that exist as individual molecules or ions, all parts have the same properties and chemical composition. For example, a spoonful of juice taken from a jugful of juice will taste the same as any sample from any part of the same jugful of juice.

A solution consists of solute, the substance that dissolves, and solvent the substance in which the solute dissolves. A solution may have one or more solutes dissolved in a given solvent. Water is the “universal solvent”.

Bronze is a solid solution of copper and tin where tin is present in a smaller amount. Hence, tin is the solute and copper is the solvent. Solutions in which water is the solvent are called aqueous solutions. Ethanol is a common solvent in medicines.

A solution is formed when two or more substances combine in such a way that one component cannot be distinguished from others. The particles of these substances are held together by intermolecular forces. These intermolecular forces also operate between solute particles and solvent that surrounds it.

The formation of a solution involves energy change, although it may be small. Some attractive interactions are broken and others are formed during the process. Solute-solvent attractive forces and solvent-solvent attractive forces are broken and these processes are always endothermic (heat-absorbing). Solute-solvent attractive forces are formed, which is an exothermic (heat-releasing) process.

For example, table salt (NaCl) dissolves readily in water because the water molecules have a sufficient attraction for each solute particle overcome the attraction of the particles in NaCl for one another. NaCl is an ionic substance (substance composed of electrically charged atoms or groups of atom called ions). The ions separate from the crystal and combine with water molecules o form hydrated ions. These will then mix with the remaining water molecules to form an intimate homogenous mixture. Hydration involves the combination of solute molecules of water. It is specific example of the process of salvation, which is term generally used to describe the combination of solute molecules or ions with solvent molecules.

Some solutions are so common to us that we give them a unique name. A solution of water and sugar is called syrup. A solution of sodium chloride (common table salt) in water is called brine. A sterilized specific concentration (0.15 molar) of sodium chloride in water is called saline. A solution of carbon dioxide in water is called seltzer, and a solution of ammonia gas in water is called ammonia water.

Other sample is a cup of cappuccino is a combination of espresso coffee, mixed with frothed hot milk or cream and often flavored with a cinnamon.

Terms:

Soluble - substance that dissolves in another substance. Examples are salt and sugars are soluble in water.

Insoluble – substance that does not dissolve in another. Example copper and mercury do not dissolve in water.

Miscible – liquids which are soluble in each other

Immiscible – liquids that do not mix

Nature of the Solution

1. The particles of solute are the size of individual small molecules or individual small ions. One nanometer is about the maximum diameter for a solute particle.

2. The mixture does not separate on standing. In a gravity environment the solution will not come apart due to any difference in density of the materials in the solution.

3. The mixture does not separate by common fiber filter. The entire solution will pass through the filter.

4. Once it is completely mixed, the mixture is homogeneous. If you take a sample of the solution from any point in the solution, the proportions of the materials will be the same.

5. The mixture appears clear rather than cloudy. It may have some color to it, but it seems to be transparent otherwise. The mixture shows no Tyndall effect. Light is not scattered by the solution. If you shine a light into the solution, the pathway of the light through the solution is not revealed to an observer out of the pathway.

6. The solute is completely dissolved into the solvent up to a point characteristic of the solvent, solute, and temperature. At a saturation point the solvent no longer can dissolve any more of the solute. If there is a saturation point, the point is distinct and characteristic of the type of materials and temperature of the solution.

7. The solution of an ionic material into water will result in an electrolyte solution. The ions of solute will separate in water to permit the solution to carry an electric current.

8. The solution shows an increase in osmotic pressure between it and a reference solution as the amount of solute is increased.

9. The solution shows an increase in boiling point as the amount of solute is increased.

10. The solution shows a decrease in melting point as the amount of solute is increased.

11. A solution of a solid non-volatile solute in a liquid solvent shows a decrease in vapor pressure above the solution as the amount of solute is increased.