SEPARATION OF MIXTURES

Chromatography is a method of separation that separates all soluble components in a solution. It requires special filter paper (uses capillary action to absorb solutions), a beaker and a dropper. When you use the dropper to put drops on the filter paper and tilt it against the inside of the beaker, you will see that the drop separates into different colors. The factors that affect how far each substance in the solution moves along the filter paper are how well the substance is held by the filter paper and the solubility of the substance.

Chromatography

Filtration

Filtration is a technique for separating a mixture of a solid and a liquid. You need filterpaper, a funnel and a flask. At the end of the process the solid will be collected in thefilter paper (called the residue) and the liquid/ solution will remain in the flask (calledthe filtrate). The advantages of this process is that both components of the mixtureare separated and both can be collected.

Hand Picking

Hand picking is a method of separating a mixture of two types solids or a solid and aliquid. In the case of two solids, they should both be easily distinguishable in order toseparate the two, either by color, size or any other factor.

Winnowing

Winnowing is a technique for separating a mixture of two solids. This method is usedif there is a great difference in weight between the two and if one of the solids is verylight and the other is relatively heavy, just enough so that it doesn’t get blown by thewind. The mixture is put in a winnowing fan and is shaken into the air so that thelighter particles are blown with he wind. This process is only used if the smallerparticles are not to be collected.

Sieving Separation of a mixture of various-sized particles, either dry or suspended in a

liquid, into two or more portions, by passing through screens of specified mesh sizes.

Separatory Funnel The separatory funnel is used separate two immiscible liquids. For this method one

liquid has to be denser than the other. The denser liquid settles at the bottom of the flask and then one can turn the knob to slowly allow the denser liquid to drip out into a beaker. It is transparent to allow the user to see clearly when the denser liquid has dripped out.

Sedimentation This method is used to separate an insoluble solid-liquid mixture. In this method

the heavier solid is allowed settle down at bottom of the container.

Decantation This method is executed after an insoluble solid-liquid mixture is allowed to

sediment. It is executed by pouring if the water while leaving the solid undisturbed.

Distillation Distillation is a method of separating mixtures based on differences in their boiling

points. Distillation is a physical separation process, and not a chemical reaction. Distillation is used separate solutions of two or more miscible liquids or a soluble solid-liquid solution. The principle behind this method is the fact that different substances have different boiling points. The solution is heated. After a while when the boiling points of one of the substances is reached the vapors of that substance are channeled into a condenser where they condense and flow into a beaker.