Types of Solution: Whenever one substance dissolves or combines well with another, it is referred to as a solution. Considering a solution, we naturally assume it results from blending solid and liquid elements. During experiments, we discovered empty areas in liquids where solid particles can easily fit. There are a variety of liquid solutions available.

This article aims to explore the meanings, components, properties, types of solutions, and so on, according to their nature. Chemistry is essential for students who plan to pursue education in fields such as medicine, chemistry, biotechnology, etc. Continue reading to learn more about the types of solutions.

Types of Solution: Overview

A solution is a homogeneous mixture of two or more substances. A homogeneous mixture means that the composition is just the same throughout. The homogeneous solution is also known as the true solution. The size of the dissolved particles in true solutions is the same as that of a molecule. Therefore, true solutions are called molecular solutions. Only soluble substances form true solutions. Salt, sugar, vinegar, metal alloys, and air are examples of solutions.

Components of Solution

The substances found in a solution are referred to as their components. Water and sugar, for example, are the components of a sugar solution.

1. Solvent: It is the component of the solution that is abundant and in which other substances are dissolved. The solvent is also the medium of the solution. For example, in a sugar solution in water, the component water is referred to as the solvent.

2. Solute: It is the substance that is dissolved in the solvent to make the solution. Sugar, for example, is referred to as a solute in a solution of sugar in water.

Properties of Solution

The important characteristic properties of a solution are as follows:

1. A solution is a homogeneous mixture.
2. Solute particles in a solution are extremely small. It has a diameter of less than \(1\,{\rm{nm}}\left( {1\,{\rm{nanometre}} = {{10}^{ – 9}}\,{\rm{metre}}} \right)\).
3. Even with a microscope, it is impossible to see the particles of a solution.
4. The particles of a solution pass through the filter paper. As a result, filtration cannot separate a solution.
5. The solutions are very stable. When a solution is kept, the solute particles do not separate from each other.
6. A true solution does not scatter light. This is because its particles are very, very small.

What are the Types of Solutions?

During the formation of a solution, any state of matter (solid, liquid, or gas) can act as both a solvent and a solute. As a result, depending on the physical states of the solute and solvent, there are nine different types of solutions:

1. Solid-Liquid Solutions
2. Liquid-Liquid Solutions
3. Gas-Liquid Solutions

1. Solid-Liquid Solution: Most solids dissolve in one liquid or the other to form homogeneous mixtures called solid-liquid solutions. In such cases, the solid is referred to as the solute and the liquid as the solvent. The solution is said to be dilute when the amount of solute is much less than the amount of solvent. If the amount of solute is relatively greater, the solution is concentrated.
   
2. Liquid-Liquid Solutions: Liquid-liquid solutions contain both solute and solvent in a liquid state. When two liquids are mixed together, the system can be homogeneous or not. We can have the following liquid-liquid systems depending on their mutual miscibility.
   
   a. Completely Miscible: Two liquids are said to be completely miscible when they mix together in all proportions to form homogeneous mixtures. A true solution is obtained by mixing two completely miscible liquids. The completely miscible liquids are of the same type, i.e. they are either polar (for example, alcohol and water) or non-polar (e.g., benzene and toluene).
   
   b. Partially miscible: When some liquid pairs are mixed together, they partially dissolve in each other, forming two distinct layers. The first layer is the solution of the first component into the second, while the second layer is the solution of the second component into the first. These liquid pairs are known as partially miscible liquid pairs. Phenol-water and triethylamine-water are two examples of partially miscible liquid pairs.
   
   c. Immiscible: Immiscible or nearly immiscible liquids are those in which two liquids do not dissolve into each other and form separate layers. Such liquid pairs include benzene-water, carbon tetrachloride-water, and others. When one liquid is polar, and the other is non-polar, the two are immiscible.
   
3. Gas-Liquid Solutions: Gas-Liquid Solutions are solutions that have a gaseous solute and a liquid solvent. For example, a mixture of carbon dioxide in water, a solution of oxygen in the water. The solubility of a gas in a liquid is determined by several factors. The important ones are:

• Nature of Gas
• Nature of Liquid
• Temperature
• Pressure

The nature of gas and the nature of solvent are important factors. Some gases are highly soluble in a particular solvent, while others are less soluble or insoluble.

Below we have tabulated the various types of solutions:

S. No.	Solute	Solvent	Type of Solution	Examples
1.	Solid	Solid	Solid in Solid	Alloy (brass, German silver, bronze, \(22\) carat gold etc.)
2.	Liquid	Solid	Liquid in Solid	Hydrated Salts, Amalgam of Hg with Na
3.	Gas	Solid	Gas in Solid	Dissolved Gases in Minerals or \({{\rm{H}}_{\rm{2}}}\) in PD
1.	Solid	Liquid	Solid in Liquid	Salt or Glucose, Sugar or Urea Solution In Water
2.	Liquid	Liquid	Liquid in Liquid	Methanol or Ethanol in Water
3.	Gas	Liquid	Gas in Liquid	Aerated Drinks, \({{\rm{O}}_{\rm{2}}}\) in Water
1.	Solid	Gas	Solid in Gas	lodine Vapour in Air, Camphor in \({{\rm{N}}_{\rm{2}}}\) Gas
2.	Liquid	Gas	Liquid in Gas	Humidity in Air, Chloroform Mixed With \({{\rm{N}}_{\rm{2}}}\) Gas
3.	Gas	Gas	Gas in Gas	Air \(\left( {{{\rm{O}}_2} + {{\rm{N}}_2}} \right)\)

Types of Solution Based on Nature of Solvent

On the basis of the nature of the solvent, solutions are of two types:

1. Aqueous Solution: An aqueous solution is one that is formed by dissolving a solid in water. Aqueous solutions include common salt solutions in water, sugar solutions in water, and detergent solutions in water. 
   
2. Non-aqueous Solution: A non-aqueous solution is one that is formed by dissolving a solid in a liquid other than water, such as alcohol, benzene, acetone, carbon disulphide, and so on.

Types of Solution Based on Concentration

Let us look at the types of solution based on concentration in the section below:

1. Concentrated Solution: A concentrated solution contains a high concentration of solute in the given solvent. Brine solution, orange juice, and dark-coloured tea are a few examples.
   
2. Diluted Solution: A dilute solution is made up of a small amount of solute and a large amount of solvent. Examples include Salt solution and light colour tea.

Types of Solution Based on Concentration of Solute in Two Solutions

Consider a cell immersed in a solution in a beaker. We can have the following types of solutions based on the concentration of solute in two solvents (in the cell and in the beaker):

1. Isotonic Solution: The solute concentration in these solutions is the same. As a result, water moves in both directions across the cell from the solution in the beaker.
   
2. Hypertonic Solution: Because the solution in the beaker has a larger solute concentration, water leaks out of the cell and into the solution in the beaker, causing the cell to plasmolysis/shrink.
   
3. Hypotonic Solution: Because the solution in the beaker contains a lower concentration of solute, water enters the cell, causing it to swell and eventually burst.

Types of Solution Based on the Amount of Solute Added

When we dissolve a solute in a solvent, we get a solution. Different amounts of solute can be dissolved in the same amount of solvent. This allows us to make a variety of solutions with varying concentrations of the same solute. The same solution may contain less dissolved solute, whereas another solution may contain more solute.

So, based on the amount of solute present, solutions are classified into three types: unsaturated solutions and saturated solutions. 

1. Unsaturated Solution: A solution in which more quantity of solute can be dissolved without raising its temperature, is called an unsaturated solution. An unsaturated solution actually contains less solute than the maximum amount of solute that can be dissolved in it at that temperature.
   For example, if more salt can be dissolved in an aqueous solution of salt without raising the temperature, the salt solution is unsaturated.
   
2. Saturated Solution: A solution in which no more solute can be dissolved at that temperature is called a saturated solution.
   For example, if no more salt can be dissolved in an aqueous salt solution at that temperature, the salt solution is said to be saturated. As a result, a saturated solution contains the most solute that can be dissolved in it at that temperature. It is obvious that a saturated solution contains more solute than an unsaturated solution.
   
3. Supersaturated Solution: A supersaturated solution is one that contains more solute than the maximum amount that can be dissolved at a given temperature.

Effect of ‘Heating’ and ‘Cooling’ on a Saturated Solution

A solution is “saturated” at a particular temperature only. So, if a saturated solution is heated to a higher temperature, it becomes unsaturated. This is due to the fact that as the temperature of the solution rises, the solute’s solubility rises, and more solute can be dissolved. If a saturated solution at a given temperature is cooled to a lower temperature, some of its dissolved solutes will separate out as solid crystals. This is due to the fact that the solubility of the solute in the solution decreases as it cools.

Summary

A solution is a homogeneous mixture of two or more substances. During the formation of a solution, any state of matter (solid, liquid, or gas) can act as both a solvent and a solute. As a result, there are nine different types of solutions depending on the solute and solvent’s physical states.

Furthermore, it is important to note that a solution is a homogeneous mixture. A true solution does not scatter light. It is also important to note that a solution is saturated at a certain temperature only. Thus, if a saturated solution is heated to a greater temperature, it becomes unsaturated.

Physiological Salt Solution

Physiological Salt Solution (PSS) contains different types of solutions, namely 10 mM NaCl, 120 mM K-MES, 20 mM imidazole, 15 mM creatine, 20 mM taurine, pH 7.2, 15 mM Na2phosphocreatine, 8 mM MgCl2, 5 mM Na2ATP, 3 mM glutamate, 5 mM K2HPO4, 3 mM malate, and more. It also mimics cardiac cells’ cytoplasm and can be classified into many.

Types of Buffer Solutions

There are major two types of buffer solutions which have been described as follows:

• Acidic Buffer
• Alkaline Buffer

Types of Colloidal Solution

The Colloidal solutions have been majorly defined in the following:

• Sol
• Emulsion
• Foam
• Aerosol

FAQs on Types of Solution

Q.1: What are the types of solid solutions?
Ans: There are two types of solid solutions. They are:
a. Substitutional Solid Solutions
b. Interstitial Solid Solutions

Q.2: What are the two main types of solutions?
Ans: On the basis of the nature of the solvent, solutions are of two types:
a. Aqueous Solution
b. Non-aqueous Solution

Q.3: What are the 10 examples of solutions?
Ans: 10 examples of solutions are- salt solution in water, sugar solution in water, urea in water, methanol solution in water, ethanol in water, aerated drinks, hydrated salt, humidity in the air, brass and \(22\) carat gold.

Q.4: What are examples of isotonic solutions?
Ans: Examples of isotonic solutions are \(0.9\% \) normal saline and lactated ringers.

Q.5: What is the true solution?
Ans: True Solution is a homogeneous mixture of two or more materials dissolved in a solvent with particle sizes less than \({10^{ – 9}}\;{\rm{m}}\) or \(1\;{\rm{nm}}\).