Concentration Of Solute

In our universe, everything around us is built up of some or the other kinds of matter. These can be categorised as solid, liquid and gas. We comprehend matter as something that maintains space around it and has some mass. The matter may take the form of a substance. In general words, a substance can be described as that state of matter which has a unique and distinctive composition. What if we combine two or more substances and make a mixture out of them? What would that be called? 

The resultant mixture that would be formed with the mixture of two or more components would be a solution. A Solution is mainly characterised as a mixture in which the particles present in the mixture have a size smaller than 1 nm. It is the composition of a solute and a solvent that makes up a solution. A solution may further be categorised into two types: dilute and concentrated solution. Dilute is the one that has more solvent and concentrated is the one that has more amount of solute in it. 

Concentration meaning 

Concentration meaning pertains to the presence of relatively high amounts of a substance in a given mixture. Being told about the presence of solute and solvent in a given mixture, the solute is characterised as the material that is existing in smaller proportions in a solution while in the case of solvent, it is interpreted as the material that is present in larger proportions in a solution. Thus, we can define the concentration of a solution as the amount of mass of a solute that is present in 100 grams of a given solution. 

How to calculate concentration?

The concentration of a solute can be defined mathematically by dividing the mass or volume of a solute to the mass or volume of a solvent or a solution.

Concentration of a solution = Mass or volume of a solute/Mass or volume of a solvent or a solution

Some formulas for characterising concentration are: 

1) Mass Concentration: It can be defined as the ratio of the mass of the solute and the volume of the solution. The units of mass concentration are kg/m³ or g/l.

2) Volume Concentration: We can define this as the ratio of the volume of solute and the volume of the mixture. 

3) Mole Ratio: With unit mol, it defines the ratio of the moles of solute in a mixture with the total moles of all the components that are present in the solution. 

4) Normality: One can deduce normality with the ratio of gram active solute in a mixture with the litres of solution. The unit of normality is depicted as N. 

5) Mass fraction: The mole fraction is defined as the moles of a solute that are present in a solution divided by the total moles of components in the mixture. 

Types of concentration of solution

1) On the basis when water is the solvent 

We can categorise concentration of solution with the presence or absence of water in it. 

• Aqueous Solution: It is the one which has water as its solvent. The examples of aqueous solution can be carbon dioxide in water, salt in water and sugar in water. 
• Non-Aqueous Solution: These are those which don’t have water as its solvent. Examples of Non-Aqueous ones are benzene, petrol, carbon disulphide and carbon tetrachloride. 

2) On the basis of proportion of solute in a mixture

One can categorise concentration of solution on the basis of the proportion of a solute in a mixture as well. 

• Saturated Solution: This refers to a solution that won’t allow adding more solute to the solvent at a given or a definite temperature.
• Unsaturated Solution: These are those that would allow adding more solute to the solvent at a given or definite temperature. In simple words, we can add more solute in it. 
• Supersaturated Solution: If more and more solute is added in a saturated solution, then it turns into a supersaturated solution. In simple words, one has forcefully added solvent by increasing the pressure or temperature of the solution. 

3) On the basis of solvent and solute in a mixture

We can categorise the concentration of solution into two categories on the basis of the solvent and solute in a mixture.

• Dilute Solution: Dilute Solutions are those solutions that have a small amount of solute, but a large proportion of solvent in it. Examples of dilute solutions are light colour tea and salt solution. 
• Concentrated Solution: Concentrated Solution is the solution having large proportions of solute in a given amount of solvent. Examples of this are dark colour tea and orange juice.  

The Concentration of solution examples are carbon dioxide in water, salt in water, sugar in water, benzene, petrol, carbon disulphide, carbon tetrachloride, light colour tea and salt solution and dark colour tea.

Conclusion

It should be noted that not all compositions of solution fall under the category of the concentration of solution. Volume concentration, mass concentration, number and molar concentration are the ones that are considered true to the definition of concentration. One can always use the above methods to categorise solutions into the various categories of concentration of solution. However, the basic formula remains the same: by dividing the mass or volume of a solute to the mass or volume of a solvent or a solution, we get concentration of a solute in a solution.