How does solubility affect a solution

For many solids dissolved in liquid water, solubility tends to correspond with increasing temperature. As water molecules heat up, they vibrate more quickly and are better able to interact with and break apart the solute. The solubility of gases displays the opposite relationship with temperature; that is, as temperature increases, gas solubility tends to decrease. In a chart of solubility vs. Pressure has a negligible effect on the solubility of solid and liquid solutes, but it has a strong effect on solutions with gaseous solutes.

This is apparent every time you open a soda can; the hissing sound from the can is due to the fact that its contents are under pressure, which ensures that the soda stays carbonated that is to say, that the carbon dioxide stays dissolved in solution. The takeaway from this is that the solubility of gases tends to correlate with increasing pressure.

If the heat given off in the dissolving reaction is less than the heat required to break apart the solid, the net dissolving reaction is endothermic. The addition of more heat facilitates the dissolving reaction by providing energy to break bonds in the solid. This is the most common situation where an increase in temperature produces an increase in solubility for solids.

The use of first-aid instant cold packs is an application of this solubility principle. A salt such as ammonium nitrate is dissolved in water after a sharp blow breaks the containers for each. The dissolving reaction is endothermic - requires heat.

Therefore the heat is drawn from the surroundings, the pack feels cold. The effect of temperature on solubility can be explained on the basis of Le Chatelier's Principle. Le Chatelier's Principle states that if a stress for example, heat, pressure, concentration of one reactant is applied to an equilibrium, the system will adjust, if possible, to minimize the effect of the stress.

This principle is of value in predicting how much a system will respond to a change in external conditions. Consider the case where the solubility process is endothermic heat added. An increase in temperature puts a stress on the equilibrium condition and causes it to shift to the right. The stress is relieved because the dissolving process consumes some of the heat. For instance, you can easily dissolve salt, sugar, or ethanol in the water where all these are polar solute and solvent.

However, it is rather challenging to dissolve a nonpolar solute like naphthalene into water. Crystallisation — When you add a solid solute into a given concentration of this liquid solvent, the particles solid gets dissolved in the solution.

This process is termed as dissolution. Crystallisation occurs when the particles of solute collide with the particles present in solution, and some of it separates from the solution. Subsequently, a dynamic equilibrium state will be achieved when the number of solute molecules entering a solution becomes equal to the number of molecules leaving it.

Further, there can be a situation wherein you cannot add more solute to the solution as it will not be dissolved. In such a case, you have reached saturation, and the solution is known as a saturated solution. Therefore, solubility can be defined as the solute concentration present in this solution at saturation for a known value of temperature and pressure.

Further addition of solute in this solution turns it into an unsaturated solution with extra undissolved solute. Since solids are highly incompressible in nature and small change in pressure have nearly no impact on it, the solubility factors like pressure do not cause many changes. On the contrary, solubility decreases if this dissolution process turns out to be exothermic. If Gases as a solute needs to be dissolved in a solvent, there are factors influencing solubility, such as temperature, nature of solvent and solute, and pressure.

There can be several gas solutes which can readily dissolve in solvent whereas few gas solutes which do not dissolve under normal conditions. For instance, you can easily dissolve ammonia or HCl into the water, but oxygen acts as a sparingly soluble substance for water. As there is a rise in temperature, the solubility of a gas solute in liquids must increase. This can be inferred from Le Chatelier's Principle. The situation is though different for gases. With increase of the temperature they became less soluble in each other and in water, but more soluble in organic solvents.

In most cases solutes dissolve in solvents that have a similar polarity. Chemists use a popular aphorism to describe this feature of solutes and solvents: "Like dissolves like". Non-polar solutes do not dissolve in polar solvents and the other way round. As for gasses the Henry's law states that solubility of gas is directly proportional to the pressure of this gas.