What makes a compound miscible

The problem was that ethanenitrile would not give up its dipole-dipole interactions for the small amount it could gain by mixing with hexane. In this case, the dipoles between dichloromethane are much smaller; they aren't held back from the hexane molecules as strongly.

On the other hand, the interaction between the the hexane and dichloromethane is actually amplified a little bit. Whereas hexane molecules rely solely on weak, transient London interactions to cling to each other, dichloromethane has a permanent dipole. That permanent dipole is able to enhance the transient dipole in hexane.

The slight tug dichloromethane exerts on hexane's electrons actually helps the two different molecules interact more strongly. Draw a solvent molecule interacting with several other identical solvent molecules. Label the strongest intermolecular force holding them together. Draw a solute molecule interacting with several other identical solute molecules. Draw one solute molecule interacting with several solvent molecules.

Predict whether the solvent will dissolve significant amounts of the solute. Solubility is conceptually similar to miscibility. If you can mix a solid with a liquid and the solid particle gets smaller and smaller until it disappears, it must have dissolved in the liquid.

At that point it may look like you are left only with the original liquid, but really the individual molecules of the solid are just distributed throughout the liquid instead of all sitting together on the bottom. You can see this when blue kool-aid powder dissolves in water to give blue kool-aid. A solution is considered saturated when adding additional solute no longer increases the concentration of the solution.

The degree of solubility ranges widely depending on the substances, from infinitely soluble fully miscible , such as ethanol in water, to poorly soluble, such as silver chloride in water. Under certain conditions, the equilibrium solubility can be exceeded, yielding a supersaturated solution.

Solubility does not depend on particle size; given enough time, even large particles will eventually dissolve. The solubility of a given solute in a given solvent typically depends on temperature.

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.

But, there are levels of immiscibility. Some solvents are soluble in each other in certain proportions. In other cases, very little of one component remains unmixed. Usually, you can tell whether two liquids are miscible just by looking at the result. Miscible liquids produce a clear liquid, while immiscible liquids yield a cloudy or layered mixture.

However, if the two liquids have the same color and similar indices of refraction, it may be difficult to see layers. Miscible solids form a homogeneous solid. Immiscible solids separate completely or else appear heterogeneous. Several factors affect miscibility. Substances with similar polarity tend to be miscible. So, polar solvents typically mix with other polar solvents, while nonpolar solvents usually mix with other nonpolar solvents.

There are exceptions, so other factors come into play. The percent weight of the hydrocarbon chain determines whether organic compounds are miscible with water. Ethanol only has two carbon atoms and is miscible with water. In contrast, 1-butanol has four carbon atoms and is immiscible with water. Polymers tend to be miscible with one another if the mixture has a lower configurational entropy than its components.