2) States of Matter Flashcards
What are aqueous solutions?
Substances dissolved in water
What process turns gas into liquid?
Condensation
What process turns liquid into solid?
Freezing
What is condensation?
When a gas is cooled to its boiling point
What are mixtures made of?
2 or more substances that haven’t been chemically combined
What techniques can separate mixtures?
Crystallisation
Chromotography
Filtration
How does filtration separate mixtures?
Mixture poured through filter paper
Insoluble solid trapped
Liquid runs through paper
How does crystallisation separate mixtures?
Heat mixture so solvent evaporates
Crystals of solute form
Collect solvent by condendsation as it evaporates
What is a solvent?
A liquid
What is a solute?
A dissolved solid
How does chromotography separate mixtures?
Dip bottom of paper into suitable solvent
Solvent moves up paper and carries the solutes with it
Solutes separate on paper
Why do different solutes separate at different places on chromotography paper?
Different solutes move at different speeds
What is crystallisation used to do?
Separate solutions into their different parts
What is chromotography used to do?
Separate solutions with a number of different solutes
What is filtration used to do?
Separate mixtures of insoluble solids and liquids
What is distillation used to do?
Separate mixtures of liquids
What are the 2 types of distillation?
Simple distillation
Fractional distillation
What is simple distillation?
Heating mixture until lower boiling point liquid boils
Water vapour passes through condenser
What is fractional distillation?
1) Heating mixture slowly until lower boiling point liquid boils and condenses
2) Continue to increase temperature to collect the other fractions
How do boiling points of pure substances and mixtures differ?
Pure substances melt or boil at sharp temperatures
Mixtures melt or boil over a range of temperatures
What are pure substances?
Substances containing only one element or compound
What are formulations?
Mixtures of chemicals that are designed to create useful products
What are examples of formulations?
Fuels
Metal alloys
Fertilisers
Medicines
Why must the quantity of component’s in formulations be monitored precisely?
To ensure the formulation does as it is supposed to
What are the 3 steps for treating waste or groundwater?
Sedimentation
Filtration
Chlorination
How is seawater trated?
Distillation to leave behind salt and other waste
What is distilled water?
Water containing no other ions or molecules
What is potable water?
Drinking water
How do impurities affect the melting and boiling points of samples?
Decreased melting point
Increased boiling point
What are the 2 phases of chromotography?
Mobile phase
Stationary phase
What can be said about the components that travel the furthest up chromotography paper?
They are highly soluble in the solvent
What is the equation for Rf values?
distance travelled by substance / disatnce travelled by solvent
What is a reference substance in chromotography?
A pure sample ran next to the tested substance to see if it’s a component in the mixture
What does chromotrography result in the production of?
Chromotograms
What are the stages of the chromotography practical?
1) Horizontal pencil line near bottom of paper
2) Place food colourings on start line along unknown subsatnces
3) Place paper in beaker with a small volume of solvent
4) Wait for solvent to travel near top of paper
5) Compare unknown spot to food colourings to identify
