Types of Solutions

In our day-to-day existence, we rarely come across pure materials. Their usage and significance in our life depend upon their composition. A solution comprises two types of components: solute and solvent. A solution is a homogeneous combination in which all particles exist as single molecules or ions. However, in a solution, the solute size varies. Through a homogenous mix, we conclude that its properties are consistent throughout the mixture. 

The components of a solution are the chemicals that make it up. A sugar solution, for example, is made up of water and sugar.  

1. Solvent: This is the abundant component of the solution in which other substances are dissolved. The solvent also serves as the solution’s medium. The component water, for example, is referred to as the solvent in a sugar solution in water.
2. Solute: A solute is a substance that is dissolved in a solvent to form a solution. 

In a sugar solution in water, the sugar is referred to as the solute.

A Solution with a lower solute concentration as compared to a solvent is called a hypotonic solution, while a solution with a high solute concentration as compared to a solvent is called a hypertonic solution. A solution with the same concentration of solute on either side of the membrane so that the cell does not bulge or recede is called an isotonic solution. 

Hypotonic Solution

A solution that has a lower amount of solute in a solution is referred to as a hypotonic solution. “Hypo” refers to less and tonic refers to strength. 

A cell contains less amount of water than a hypotonic solution. Pure water is also a hypotonic solution. If a red blood cell is placed under a hypotonic solution, then the red blood cell will fill up with the hypotonic solution as the red blood cell has no cell wall. The solution will produce enough pressure, and eventually, the red blood cell will burst. This is the purpose when we pour water on a bloodstain, and the fabric makes the smudge worse. In biology, the solution outside of the cell is called a hypotonic solution if the cytosol of the cell has more solutes than the solution. But in the case of a plant cell, it possesses a cell wall. So when a plant cell is placed under a hypotonic solution, the central part, which is the vacuole, takes up the additional water and tugs the cell membrane against the cell wall.  But the nature of the cell wall is rigid, so it drags back, prohibiting cells from bursting. A hypotonic solution has low osmotic pressure.

Hypertonic Solution

“Hyper” refers to more and “tonic” refers to strength. A solution that has more amount of solute than solvent in a solution is referred to as a hypertonic solution. If the cytosol of the cell is a hypertonic solution, then it suggests that the surrounding environment is of hypotonic solution. The solute and the solvent flow according to their concentration gradient. Saltwater is a hypertonic solution. 

If a cell is set under a hypertonic solution, the osmotic pressure manages to move the water outside of the cell to equalise the concentrations on either side of the cell membrane. In the vacuole part of the plant cell, there is the hypertonic solution. The plant cell uses that hypertonic solution to draw water into the vacuole. By this, the turgor pressure is increased within the cell. The nerve cells of animals depend on the hypertonic solution ions. The ions generate an action potential. Hypertonic solutions retain comparatively high osmotic pressure. 

Isotonic Solution

A solution that contains the same amount of solute and solvent is known as an isotonic solution. 

Isotonic solutions retain balanced osmotic pressure. This type of solution indicates no effect on the cell. Also, they are not useful in food preservation. 

If a cell is positioned under an isotonic solution, there will be no movement of water inside or outside the cell. Hence, the volume of the cell remains constant as there is no exchange of solute or solvent. 0.9% NaCl (Normal Saline) and lactated ringers are one example of an isotonic solution. Patients with nausea, dehydration, and vomiting are treated with these fluids. In biology, some cells are retained in an osmotic solution to benefit cellular processes. Most of the animals conserve the osmolarity and pH of the fluids inside their body to develop isotonic solutions to saturate their cells. Equal to the amount inside the cell, this solution carries water and nutrients.

Different Kinds of Solutions

A state of matter which is solid liquid or gas can act as a solute or a solvent while preparing the solution. As a result, there are nine different types of solutions depending on the physical states of the solute and solvent. 

1. Solid-Liquid solution

The majority of solids dissolve in one of two liquids resulting in homogeneous mixtures known as solid-liquid solutions. The solid is referred to as the solute, while the liquid is referred to as the solvent in such an instance. The solution is known to be dilute when the proportion of solute is substantially less than the amount of solvent.

2. Liquid-Liquid Solutions

Liquid-liquid solutions are liquid solutions that contain both the solute and the solvent. 

When two liquids are combined, the system can be homogeneous or non-homogeneous. 

3. Liquid-Gas Solutions

An example of this type of solution is  a mixture of carbon dioxide and water, or oxygen in water. Several factors influence the solubility of a gas in a liquid. The most crucial ones are gaseous nature, liquid nature, temperature, and pressure. The important aspects include the composition of the gas and the type of solvent. Some gases are extremely soluble in a 

given solvent, while others are either insoluble or barely soluble.

Based on the amount of solute added, many types of solutions exist.

We get a solution when we dissolve a solute in a solvent. In the same amount of solvent,  

different amounts of solute can be dissolved. This enables us to create a wide range of solutions containing different amounts of the same solute.

Solutions are categorised into three categories based on the amount of solute present: 

unsaturated solutions, saturated solutions, and neutral solutions. 

1. Unsaturated Solution

A solution in which a greater amount of solute can be dissolved. An unsaturated solution can be dissolved without raising its temperature. At a given temperature,  an unsaturated solution contains less solute than the maximum quantity of solute that may be dissolved in it. The salt solution is unsaturated if more salt can be dissolved in an aqueous solution of salt without altering the temperature. 

2. Saturated Solution

A saturated solution is one in which no more solute can be dissolved at that temperature. A saturated solution contains more solute than an unsaturated solution, which is self-evident. 

3. Supersaturated Solution

A supersaturated solution contains more solute than can be dissolved at a given temperature. An example is a mercury amalgam, a mixture of mercury and another metal.

Conclusion

A hypotonic solution is a type of solution which encompasses anything that contains more water and limited solute compared to the cells. A hypertonic solution is a kind of solution which encompasses anything that contains more electrolytes or molecules than solvent or water. Both solutions behave according to their properties. Both the solutions play a pivotal role in the living systems of plants as well as animals.