4.1 : miscibility and solutions Flashcards
what is solubility?
solubility describes a solute dissolving, mixing or combining with a solvent regardless of the state of either substances.
what is miscibility?
miscibility describes liquids which can be mixed together to form a single liquid.
why are hydrocarbons non-polar?
hydrocarbons are non polar due to the small difference in electronegativity between the carbon (2.5) and hydrogen (2.1) atoms present in the hydrocarbon.
what is the basic rule of solubility?
the basic and fundamental rule of solubility is that “like dissolves like”, meaning a polar solvent will dissolve a polar solute and a non-polar solvent will dissolve a non-polar solute.
- solutes and solvents with intermolecular forces of similar strengths are likely to dissolve in one another.
how do functional groups affect a molecule’s solubility?
both the hydroxyl and carboxyl group are polar groups located on hydrocarbons. Small polar molecules of alcohol and carboxylic acids are more soluble in water than larger molecules of similar polarity. This is as a result of the polar portion of the molecule contributing to more to the overall characteristics of the molecule. As the length of the carbon chain increases, the molecule tends to exhibit more non-polar characteristics.
how does mass and size affect a molecule’s solubility?
the larger the solute particles are, the more difficult it is for a solvent’s particles to separate and surround other molecules. the molecules within the solvent must be able to disrupt the existing intermolecular forces operating between solute molecules.
general rule: as size and subsequent molecular mass of a molecule increases, its miscibility decreases.
what is a surfactant?
a compound with non-polar and polar components that facilitate the mixing of polar and non-polar substances.
what do hydrophobic and hydrophilic mean?
hydrophobic implies hating water and hydrophilic means being attracted to water.
what is an emulsion?
an emulsion is a fine dispersion of one liquid in another which is not miscible, ie. an emulsion of water and droplets of oil.
