Separation techniques and the periodic table Flashcards
What is a mixture?
A mixture is two different substance wich are not chemically combined.
What is a solution?
A solution forms when a solute dissolves in a solvent.
A solution is a specific type of mixture where one substance is dissolved into another.
How can you tell if something is a pure substance?
Pure substances have a sharp melting point but mixtures melt over a range of temperatures.
Name 4 ways you can separate a mixture
Distillation
Evaporation
Chromatography
Filtration
What is evaporation?
Where water turns from a liquid to gas vapour.
Evaporation is used to separate a soluble solid from a liquid. For example, copper sulfate is soluble in water – its crystals dissolve in water to form copper sulfate solution. During evaporation, the water evaporates away leaving solid copper sulfate crystals behind
What is distillation?
Simple distillation is a method for separating the solvent from a solution. When the solution is heated, the water evaporates. It is then cooled and condensed into a separate container. The salt does not evaporate and so it stays behind
How are evaporation and distillation different?
In evaporation the liquid does not get changed back into a liquid in distillation you catch the steam and it turns back into water. The main difference between evaporation and distillation is that 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
One beaker contains a mixture of solid and liquid, the other contains a funnel with filter paper.
The solid and liquid mixture is poured into the filter funnel.
The liquid drips through the filter paper but the solid particles are caught in the filter paper.
Why can’t you separate a solvent from a solute using filtration?
Because the solvent will dissolve into the solute so when you filter it the solvent will be small enough to go through with the solute and you will still be left with a mixture.
What is chromatography used for?
Chromatography is a process for separating components of a mixture. It is used for Creating vaccinations. Chromatography is useful in determining which antibodies fight various diseases and viruses, Food testing, Beverage testing, Drug testing, Forensic testing.
Describe how to carry out chromatography
Simple chromatography is carried out on paper. A spot of the mixture is placed near the bottom of a piece of chromatography paper. The paper is then placed upright in a suitable 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?
Groups
What are the rows of the periodic table called?
Periods
Describe a trend of the group 1 elements
The reactivity of group 1 elements increases as you go down the group
Describe a trend of the group 7 elements
The melting points and boiling points of the halogens increase going down group 7
