An Introduction to Solutions

A solution is a specific kind of combination. In chemistry, mixtures are made up of several compounds, each preserving its chemical characteristics. In general, non-chemical methods such as filtering, heating, and spinning can separate mixtures. A solution is a homogenous combination, but that is not all there is more to it.

The term “homogeneous” refers to a combination that is the same throughout. Two identical-sized samples, one in the bottom, the other from the top, might be taken. When uninterrupted, homogeneous mixes do not settle out, but heterogeneous mixtures do.

Example of Solutions

You have probably seen a variety of remedies, including soda water, sharbat, salt solution, and so on. You have probably encountered brass utensils, which seem to be likewise homogeneous solid-solid solutions. Solid-liquid, solid-solid, solid-gas, liquid-solid, liquid-liquid, gas-solid, gas-liquid, & gas-gas combinations are all possible. Solutions include gasoline, metals, air, starch solution, etc.

Solutions Consist of -Solute and Solvent

Solute

The solute is the component dissolved in a solvent to produce a solution. It is present in the mixture in smaller amounts than the solvent.

Solvent

A solvent is the element of a mixture in which a solute dissolves. It is present in higher amounts in solution than the solute.

Example: When we take a saltwater mixture, salt is a solute in this solution, & water is a solvent because salt is dissolved; hence salt is present in the solution in fewer amounts than water.

As a result, we may say that the solvent makes up a significant fraction of the solution.

Composition of Solutions

Solutions include sugar-water, salt solution, metals, alloys, liquor in water, aerosol, air, and aerated beverages such as Coca-Cola, among others. We make various solutions while working with chemistry, including copper in water, iodine in alcohol, and so on.

Solution Characteristics

The qualities of a solution are as follows:

1. A homogenous mixture is referred to as a solution.
2. A solution’s component particles have a diameter of less than 10-9 metres.
3. The constituent particles of such a solution are invisible to the human eye.
4. A ray of light travelling through a solution is not scattered.
5. As a result, the route of the light beam is hidden in solutions.
6. Filtration cannot distinguish solute particles.
7. When left uninterrupted, solute or solvent molecules do not settle.
8. At a certain temperature, solutions are stable.

Types of Solutions Based on Solute Quantity

Based on the number of solutes in the solution, solutions can be classified into the following categories:

• Unsaturated solution
• Saturated solution
• Supersaturated solution

Unsaturated Solution

Unsaturated solutions are those where we can add additional solutes at a specific temperature. Example: mist

Saturated Solution

A saturated solution is one in which we cannot dissolve any further solute in the solvent at a particular temperature. Example : seawater

Supersaturated Solution

A supersaturated solution is a saturated solution to which extra solute is added by increasing the temperature or pressure. Generally, crystals begin to form in these solutions.Example: sugar syrup.

Different types of solutions are classified according to the number of solvents used.

Concentrated solution

A concentrated solution is one where the solute is present in large quantities.Example: Brine solution

Dilute solution

It contains a tiny amount of solute in a huge volume of solvent.Example: Tap water

Solubility

A substance’s solubility refers to the greatest amount that may be absorbed in a solvent volume at a given temperature.

Factors that Influence a Substance’s Solubility

• The nature of the solute
• The nature of the solvent
• Temperature
• Pressure

Solubility of a Solid inside a Liquid is the ability of a solid to dissolve in a liquid.

Non-polar solutes are absorbed in non-polar solvents, whereas polar solutes are absorbed in polar solvents. It signifies that not all materials dissolve in all kinds of liquids. Polar liquid solvents absorb solid polar molecules, while non-polar liquid solvents absorb non-polar solid substances.

The Principal of Le Chandelier

Temperature fluctuations impact the absorption of a solid in a liquid solution. In these solutions, dynamic equilibrium should obey Le Chatelier’s principle.

• The dissolving process is endothermic (H > 0) for just a fully saturated solution. The solubility increases even as temperature increases in this situation.
• The solubility of the exothermic reaction (∆H < 0) reduces as the temperature increases.

Liquids and solids are highly viscous or slightly compressible. Therefore, pressure changes have little effect. That is why pressure does not affect a solid’s absorption in a liquid.

Solubility of a Gas inside a Liquid 

Pressure and temperature have a big impact on a gas’s solubility in a liquid.

Henry’s Law

Henry’s law was named after William Henry, an English chemist that was the first to define a quantitative relationship among pressure & gas solubility inside a solvent. The law says that the absorption of a gas in a liquid is exactly proportional to the fraction of the gas existing above the liquid or solution’s surface at a specific temperature.

‘Dalton demonstrated that a gas’s solubility in a liquid solution is indeed a function of the gas’s partial pressure. The partial pressure of the gas above the solution is proportional to the molar concentration of gas in the solution.

Conclusion:

In chemistry, a solution is indeed a homogeneous combination of various compounds in relative proportions that may be changed continuously to a solubility limit. This term “solution” is most frequently associated with the fluid form of matter. However, gases and solids can also form solutions. For instance, the air is indeed a solution made up of nitrogen and oxygen plus small quantities of various other gases, whereas brass is indeed a solution made up of zinc and copper. 

Solutions play an important role in living systems. Oxygen from the lungs dissolves in the bloodstream, combines chemically with haemoglobin in red blood cells, and can then be delivered to the body tissue. Digestive byproducts are also conveyed in solution to various portions of the body.