Methods of Separating Mixtures How can mixtures be separated? This ppt introduces and reviews ways of separating mixtures

If you have a salad containing an ingredient you don't like, how can you remove it? Many mixtures are not as easy to separate.

To separate a mixture of olive oil and vinegar, for example, you could decant, or pour off, the oil layer. (Density, oil floats on water) Or, you might cool the mixture until the oil turned solid. (Differences in the freezing point of the substances) Freezing point (C) Substance water -2.0 Vinegar 2.8 Olive oil

Mixtures vs Pure substances Mixtures can be separated by differences in the physical properties of the substances they are composed of. Pure substances cannot be separated by physical methods.

Physical properties Melting point Boiling point Freezing point Density Electrical conductivity Magnetic Particle size

a) Magnet b) Filtration c) Decanting d) Chromatography e) Distillation How can we physically separate (purify) substances from mixtures and solutions into pure substances? a) Magnet b) Filtration c) Decanting d) Chromatography e) Distillation Physical means are those that do not change the nature of the substances being separated.

A magnet Can be used to separate a magnetic substance from a non-magnetic substance (Magnetic properties) Magnets are used in the re-cycling industry to separate ferrous and non ferrous metals.

Filtration Funnel Filtration can be used to separate an insoluble substance from a soluble substance (heterogenous mixture) Ex. Coffee grounds are separated by water through filtration Solid Here you can introduce the terms Filtrate and residue. Liquid Filter paper used in a laboratory is similar to coffee filters.

Filtration The coffee filter can separate ground coffee beans from brewed coffee. The liquid brewed coffee passes through the paper filter, but the solid coffee grounds cannot pass through the filter.

Filtration-Sieving Separation of particles from a mixture based on difference in size of particles. Separation of coarse particles from finer particles.

Decant To decant – pour the liquids off and leave the solids behind.

Chromatography From Greek Chroma which means "color" and graphein "to write" Technique for the separation of complex mixtures that rely on the differential affinities of substances Ex. Paper chromatography separate black ink into the colored dyes it contains.

Distillation Separate substances that have different boiling points Ex. Separating alcohol from water Boiling pt of alcohol is 70 C. Boiling pt of water is 100 C. The liquid is boiled to produce a vapor that is then condensed into a liquid.

Tap water is a homogeneous mixture of water and substances that are dissolved in the water. One way to separate water from the other components in tap water is through distillation.

Separating a Heterogeneous Mixture Sample Problem Separating a Heterogeneous Mixture How could a mixture of aluminum nails and iron nails be separated? Analyze Identify the relevant concepts. 1 In order to identify how to separate aluminum and iron nails, the properties of both aluminum and iron must be known. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved

Solve Apply concepts to this situation. Sample Problem Solve Apply concepts to this situation. 2 List the properties of each substance in the mixture. Aluminum metal gray color doesn’t dissolve in water not attracted to magnet Iron metal gray color doesn’t dissolve in water attracted to magnet

Solve Apply concepts to this situation. Sample Problem Solve Apply concepts to this situation. 2 Identify a property that can be used to separate different substances from each other. The ability to be attracted by a magnet is a property that iron and aluminum do not share. You could use a magnet to remove the iron nails from a mixture of iron and aluminum.

Distillation relies on the boiling point of the substance. Which physical property does filtration rely on to separate mixtures? Which does distillation rely on? Filtration relies on the size of a particle, or molecule, of a substance. Distillation relies on the boiling point of the substance.