Which physical property allows us to separate components of a mixture?

Answer 1

If you mix two liquids they can be separated by fractional distillation. If you mix two solids, eg, sulphur and salt they can be separated by dissolving one substance in a liquid in which the other is insoluble. If you mix two gases they can be separated in a centrifuge.

Answer 2

There are various ways to do this, but they typically use the physical properties mass or electromagnetic attraction.

This isn't an example of separating a mixture out for later use, but in chemistry the chemical composition of a given material can be determined using a process called mass spectroscopy. This principle uses Newton's laws of motion, specifically the equation F=ma which tells us that if we apply a set force to an object then we can use its rate of acceleration to determine its mass - and this is exactly what mass spectroscopy does. It first breaks down the compounds into smaller fragments and then fires them all out towards a detector (but not straight up! they will be fired at some angle across so that gravity will curve its trajectory). The heavier compounds accelerate horizontally slower than the lighter ones, so they are influenced more by gravity and so particle are heavier if they are detected at a lower level.

Another good example is a centrifuge, which uses high speed circular motion to a similar effect.

The easiest way to explain electromagnetic attraction is to think of a bucket full of steel nails and wooden pegs. If you wanted to get all of the steel nails separate from the wooden pegs your could simply use a strong magnet.

Electromagnetism can be used in a similar way to mass spectroscopy.

Answer 3

One example would be the separation of a liquid/solid mixture. By centrifugally concentrating the solid at the bottom of the mixture, then decanting (pouring off) the liquid.

Answer 4

Magnetism? Solubility? Size? Density? Pick one.

Answer 5

Filtration