Separation techniques and the periodic table Flashcards
What is a mixture?
A mixture is a material made up of two or more different substances which are not chemically combined.
What is a solution?
A mixture composed of two or more substances.
What is a pure substance?
A pure substance does not have to be of a single element or compound.
How can you tell if something is a pure substance?
pure substances have a specific melting points mixtures melt over a range of temperatures.
Name 4 ways you can separate a mixture
Chromatography involves solvent separation on a solid medium. Distillation takes advantage of differences in boiling points. Evaporation removes a liquid from a solution to leave a solid material. Filtration separates solids of different sizes.
What is evaporation?
liquid turning into vapour.
What is distillation?
the action of purifying a liquid by a process of heating and cooling.
How are evaporation and distillation different?
evaporation is a process that involves a change in the state of matter while distillation is a process of separation.
Describe how to carry out filtration
When a mixture of sand and water is filtered: the sand stays behind in the filter paper the water passes through the filter paper.
Why can’t you separate a solvent from a solute using filtration?
Filtration works when the solute isn’t dissolve in the solvent.
What is chromatography used for?
separating a mixture of chemical substances into its individual components
Describe how to carry out chromatography
Adot of mixture is put at the bottom of a piece of chromatography paper. The paper is then placed upright in a solvent , such as water. As the solvent soaks up the paper, it carries the mixtures with it.
What are the columns of the periodic table called?
The horizontal rows are called periods.
What are the rows of the periodic table called?
The vertical columns are called groups.
Describe a trend of the group 1 elements
the atoms become larger.
