Mixtures Flashcards
What do pure substances have that mixtures do not have?
Pure substances have specific properties that distinguish them from all others
What properties do mixtures have?
No special, unique properties
Can the components of a mixture be extracted?
Yes
What are the two properties of a heterogenous substance? What is it also known as?
The components can be seen by the eye and are not evenly distributed. A mixture.
What are the two properties of a homogeneous substance? What is it also known as?
Each compound cannot be seen or separated. A solution.
What is distillation?
A method used to separate out separate compounds within a substance by heating each compound to its boiling point
What composition does a pure substance have?
The same composition throughout.
Where in the liquid do the particles need the less energy to turn to gas?
The surface
What’s the melting point of a mixture?
The melting point is different for every substance of the mixture
What happens to the particles when a solid melts
The particles gain energy and begin to move apart
What has to be overcome for a solid to begin melting?
The weak forces of attraction
What composition does a pure substance have?
The same composition throughout
When does a pure substance melt?
All the substance melts at the same point until all of it has changes from a solid to a liquid
In a mixture what is important about the physical properties?
All physical properties are NOT the same throughout
When does a mixture melt?
All substances in a mixture melt at different points
What is paper chromatography?
A cheap and easy way to separate the different pots of a mixture
Why does chromatography work?
Because different solute dissolve with differing success in different solvente
How does the solubility of the compound effect how fast it will travel up the paper in chromatography?
The more soluble the compound is, the faster it is carried up the paper
What is the paper you are left with at the end of chromatography called?
A chromatogram
Why does the distance a due travels up the paper tell us about it in chromatography?
The dye that travels furthest up the paper is the most soluble
What is the Stationary phase in chromatography?
Stationary phase = dye is not moving
What is the mobile phase in chromatography?
The solvent
What is the equation for RF values?
RF = distance moved by compound / distance moved by solvent
What is a Mixture?
A mixture is two or more compounds/elements that are not chemically joined
