9.2 Lifestyle Chemistry: Mixtures and Solutions

Important terms:

•Solute = A solid that dissolves into a solution

•Solvent = the substance in which a solute dissolves

•Solution = contains dissolved substances that are uniform throughout, is transparent and may be coloured; the solute is dissolved entirely in the solvent

•Mixture =  two or more substances not chemically combined

•Colloid = mixtures where large molecules or small clusters of molecules are dispersed through the liquid and do not settle out

•Homogenous = Evenly distributed

•Heterogeneous = Unevenly distributed

Types of mixtures:

•Suspension = insoluble solids suspended in liquids; the solids eventually settle upon standing

•Colloid = mixtures where large molecules or small clusters of molecules are dispersed through the liquid and do not settle out

•Emulsion = dispersion of a liquid in another liquid in which it is immiscible

•Solutions appear clear, leave no residue when filtered and a light beam cannot be seen in the solution.

•Suspensions contain insoluble solids that will eventually settle, forming layers upon standing. Residue is left when filtered and a beam of light can be seen in the suspension.

•Colloids are mixtures of large molecules or small clusters of molecules dispersed in a liquid. Colloids are not clear, a beam of light can be seen in the colloid, and no residue is left after filtering.

Examples of colloids:

•Solid-in-liquid such as water-based paint, ink, jelly, toothpaste

•Gas-in-liquid foams such as mousse, whipped cream

•Liquid-in-liquid emulsions such as oil-in-water or water-in-oil.

Questions:

•Compare a solution to a colloid

•Explain why water is important in the human body

•Describe an advantage of a highly stable colloid