chapter 4 (separation techniques) secondary 1 Flashcards
What method is used to separate a mixture of magnetic and non-magnetic materials?
Magnetic attraction.
How do we separate a mixture of something with different particle sizes?
We use filtration.
How does filtration work?
Filter paper with pores which are of a particular size is used. Particles of that size will pass through. Particles that are not of that size will not pass through, and the substances in the mixture are thus separated.
What is the solid left behind when a substance undergo’s filtration?
Residue.
What is the liquid that passes through the filter paper when a substance is undergoing filtration?
Filtrate.
How do we separate a solute and a solvent?
Use the separation method of evaporation.
Why does evaporating work in separating a solute and a solvent?
The solvent usually evaporates at a much lower temperature than the solute.
How do we separate a mixture of different substances at different boiling points?
Use distillation.
What is the purpose of boiling chips in the process of distillation?
To ensure smooth boiling.
How does distillation work?
A mixture is boiled and the substance with the lowest boiling point evaporates first before coming into contact with a cooler surface and thus losing heat and condensing. The mixture is then separated. (unless there are more substances in the mixture)
What does paper chromatography do?
Separates a mixture of substances that dissolve to different extents.
How does paper chromatography work?
A starting line is drawn on a piece of paper. Them, a drop of ink is placed in it. Substances in the ink that are more soluble in the solvent will travel a further distance from the starting line drawn. Substances that are insoluble will remain at the starting line.
Why do we need to use a pencil to draw the starting line in paper chromatography?
Pencil lead is unable to dissolve, so by using a pencil, it will not affect the results of the experiment.
