S 1.1 Flashcards
Classify matter
All matter
-Pure Substances: Elements, Compounds
-Mixtures: Heterogeneous, Homogeneous
What are elements?
Pure substances that cannot be broken down into simpler substances.
What are compounds?
Atoms of different elements chemically bonded together in a fixed ratio.
What changes between compounds and elements
Their physical properties are completely different for those of their component elements.
What is a chemical formula?
Combination of symbols of its elements with a subscript that is used to show the number of atoms of each element in a unit of the compound.
What is a homogeneous mixture
The inter particle attraction within the different components must be similar in nature to those between the components in the mixture
What is a heterogeneous mixture?
Non-uniform composition. Properties are not the same throughout.
How can different components in a mixture be separated (because of what)
If they have distinct physical properties.
Explain the process of filtration
Solid is separated from a liquid or gas using a membrane. The solid is collected on the membrane as the residue and the filtrate with the solution passes through.
Explain the process of evaporation
Water can be separated by a salt by evaporation, which allows the salt crystals to crystallize.
Explain the process of distillation
Separate solvent from solute. Solvent has a lower boiling point than the solute, so that it is collected as a gas and passes into the condensing tube which is surrounded by cold flowing water. Gas is condensed into the pure solvent collected in the beaker at the bottom.
Explain the process of paper chromatography
Small spots of solutions containing the samples being tested are placed on the baseline. The paper is suspended to ensure that it is saturated. Different components have different affinities for the water in the paper and so separates as the solvent moves up the paper.
What are states of matter
Matter exists in different states as determined by the temperature and the pressure
The kinetic molecular theory-Solids
Particles are closely packed together
-Inter particle forces are strong, vibrate in position
-Fixed shape
-Fixed volume
The kinetic molecular theory- Liquids
-Particles are more spaced
-Inter particle forces are weaker, particles can slide over eachother
-No fixed shape
-No fixed volume
The kinetic molecular theory- Gas
-Particles fully spread out
-Inter particle forces are weak, move freely
-No fixed shape
-No fixed volume.
What is the temperature of a system related to?
The average kinetic energy of the particles and the state of matter at a given temperature.
What is the pressure of a system related to?
Strength of inter-particle forces that exist between particles.
Explain the boiling process
-Boiling point is the temperature at which the vapour is equal to the external pressure
-Liquid is heated, more particles enter the vapour state and the pressure increases
-When the vapour pressure reaches the external atmosphere pressure it boils
-When the external pressure is lower than the vapour pressure, it is reduced and boiling point occurs at a lower temperature.
Explain state changing
Vibrations are sufficiently energetic for the particles to move away from their fixed positions and form whatever. Energy added during this stage is used to break the inter particle forces, not to raise the kinetic energy so the temperature remains constant.
How to transform from celcius to kelvin
+273º
Where is the total kinetic energy conserved in?
The collisions.
How do you calculate the Rf value?
distance moved by component/distance moved by solvent
