Separation Techniques Flashcards

All 8 cards in this deck

Which separation technique separates an insoluble solid from a liquid?

Filtration.
The solid stays on the filter paper as the residue; the liquid passing through is the filtrate.

What are the steps of simple distillation to obtain pure water from a solution?
e.g. separating water from salty water

1. Heat the solution in the flask so the water evaporates.
2. The vapour passes into the condenser and is cooled back to liquid.
3. Pure water is collected in a beaker; the dissolved solid stays in the flask.

What are the steps to obtain crystals of a soluble solid from its solution?
e.g. copper sulfate crystals from copper sulfate solution

1. Heat the solution in an evaporating basin until it is concentrated (crystals appear at the edge).
2. Leave it to cool so crystals form.
3. Separate the crystals and dry them between filter papers or in a warm oven.

What does fractional distillation separate, and on what property?

A mixture of liquids (miscible), separated by their different boiling points.

Why should the thermometer bulb be level with the side arm in simple distillation?

To measure the temperature (boiling point) of the vapour passing into the condenser.

True or false? Filtration can be used to separate a dissolved salt from its solution.

False. Dissolved salt passes through the filter paper; use crystallisation or distillation instead.

In fractional distillation, which liquid in the mixture is collected first?

The liquid with the lowest boiling point.

Simple distillation only works well when the substances being separated have what kind of boiling points?

Very different boiling points.
Liquids with similar boiling points need fractional distillation instead.