Difference Between Soluble and Insoluble

Soluble vs Insoluble
 

Solubility and insolubility of material in a solvent is very important. It is even the fundamental phenomenon for the generation of life on earth and the continuation of it. There should be various chemical and physical interactions for a substance to be soluble and insoluble. Here, we will consider these two terms in a broader perspective.

Soluble

Solvent is a substance with dissolving capability, thus can dissolve another substance. Solvents can be in a liquid, gaseous or solid state. Solute is a substance that is soluble in a solvent in order to form a solution. Solutes can be in liquid, gaseous or solid phase. So, solubility/soluble is the ability of a solute to dissolve in a solvent. The degree of solubility depends on various factors like the type of solvent and solute, temperature, pressure, stirring speed, saturation level of the solution, etc. Substances are soluble in each other only if they are alike (“likes dissolve likes”). For example, polar substances are soluble in polar solvents but not in non-polar solvents. Sugar molecules have weak inter molecular interactions between them. When dissolved in water, these interactions will break, and molecules will be apart. Bond breakages need energy. This energy will be supplied by the formation of hydrogen bonds with water molecules. Because of this process, sugar is well soluble in water. Similarly, when a salt like sodium chloride dissolves in water, the sodium and chloride ions are released, and they will interact with polar water molecules. The conclusion we can arrive from the above two examples is that, the solutes will give their elementary particles upon dissolving in solubility. When a substance is first added to a solvent, first it will dissolve rapidly. After sometime, a reversible reaction establishes, and the dissolving rate will decrease. Once the dissolving rate and the precipitating rate are equal, the solution is said to be at solubility equilibrium. This type of solution is known as a saturated solution.

Insoluble

Insoluble means that cannot be dissolved. It is the opposite of soluble. As mentioned above, substances dissolve with each other if they “like” each other. When they “don’t like” each other they are insoluble. In other words, if two substances cannot interact with each other, they won’t be soluble. For example, polar substances and non-polar substances do not like each other; therefore, there aren’t any interactions between them. So, non-polar solute will not be soluble in a polar solvent. For example, piece of rubber doesn’t soluble in water. Else sugar is not soluble in oil. Insoluble material can be separated easily by filtration method. As there are substances which are completely insoluble, there can be some which are partly soluble. If the solute and the solvent can make interactions for some degree, they are partly soluble.