Section 1- Particles and Mixtures P1 Flashcards
What are the three states of matter?
Solid, liquid, gas
What process causes solids to turn into a liquid?
melting
What process causes a liquid to change into a solid?
Freezing
What process causes a liquid to change into a gas?
Evaporating
What process changes a gas into a liquid?
Condensing
What process changes a solid into a gas?
Subliming
What three factors affect the forces of attraction between the particles of a material and thus affect the sate of matter of a material?
the material
the temperature
the pressure
What are the properties of solids?
- strong forces of attraction between particles
- particles are close together in fixed positions to form a lattice arrangement
- keep a definite shape and volume
- particles vibrate about their position (solids expand when heated because of the vibrations)
What are the properties of liquids?
- weak forces of attraction between particles
- randomly arranged particles, free to move past each other
- have a definite volume but not a definite shape
- particles are constantly moving in random directions
- liquids expand when heated
What are the properties of gases?
- very weak forces of attraction between particles
- particles are free to move and far apart and travel in straight lines
- don’t have a definite shape or volume
- constantly in random motion
- gases expand when heated or when the pressure increases
What’s diffusion?
Diffusion is the net movement of particles from an area of high concentration to an area of low concentration through a liquid or gas.
What are examples of diffusion?
- potassium manganate(VII) and water
- ammonia and hydrogen chloride
- bromine gas and air
How is potassium manganate(VII) and water an example of diffusion?
Potassium manganate is bright purple so it’s great for visualising diffusion.
- the random motion of the particles cause it to evenly spread out
- if you add more water it becomes more diluted
How is ammonia and hydrogen chloride an example of diffusion?
A white ring of ammonium chloride will form closer to the hydrochloric acid end of the tube.
-it forms closer to the hydrochloric acid end because the ammonia particles are lighter and smaller
How is bromine gas and air an example of diffusion?
- bromine is a brown strong smelling gas
- fill a glass jar full of bromine gas and another with air separate them with a glass plate
- when you remove the glass plate the bromine gas will slowly diffuse through the air
What is a solution?
A solution is a mixture of a solvent and a solute
Define dissolving:
When you add a solid(solute) and a liquid(solvent) the bonds holding the solute molecules together sometimes break and then the molecules mix with the solvent forming a solution
Define solution:
a mixture of a solute and a solvent that doesn’t separate out
Define solute:
the substance being dissolved
Define solvent:
the liquid it is being dissolved into
Define saturated solution:
a solution where the maximum amount of solute has been dissolved, so no more solute will dissolve in the solution
What are the 3 sub-atomic particles which make up an atom?
Protons
Neutrons
Electrons
What do the numbers above and below the letters on the periodic table mean?
Top number-mass number
Bottom number-proton/atomic number
What is the energy levels/ energy shells?
The (line) around the nucleus which the electrons orbit on.
What is the relative mass and charge of a proton?
Relative mass:1
Charge:+1
What is the relative mass and charge of a neutron?
Relative mass:1
Charge:0
What is the relative mass and charge of a electron?
Relative mass:1/2000
Charge:-1
No. of protons in an atom =
No. of electrons (so atoms have no overall charge)
Describe a diagram of an atom:
In the centre there are the protons and neutrons in the nucleus(which can represented as a circle round the protons and neutrons) and the big circles around represent the energy shells/energy levels and the electrons are on the energy shells/energy levels
What are some key features of the nucleus of an atom?
- in the middle of an atom
- contains protons and neutrons
- has a positive charge because of the protons
- almost the whole mass of the atom is concentrated in the nucleus
What are some key features of the electrons of an atom?
- move around the nucleus in energy levels called shells
- they are negatively charged
- they are tiny, but their orbitals cover a lot of space
- the size of their orbitals determines the atom
How do you work out the mass number?
Mass number=No. of protons+No. of neutrons
No. of neutrons=Mass number-Proton number
Define Molecule:
A molecule is a particle that contains more than one atom, chemically bonded together. There can be molecules of compounds or elements.
What are isotopes?
Isotopes are atoms of the same element that have the same number of protons but different number of neutrons.
What does the proton number define?
It defines the element.
What does the mass number define?
The mass number defines the isotope.
How do you name isotopes?
They are called the element-the mass number.
For an isotope what properties stay the same and what properties change?
CHEMICAL PROPERTIES - The electrons determine the chemical properties of an element - STAY THE SAME
PHYSICAL PROPERTIES - Physical properties such as melting point, boiling point and density - CHANGE
What is the relative atomic mass?
RAM is the average mass of the element.
How do you work out the relative atomic mass?
RAM=(mass of A1 x % of A1) + (mass of A2 x % of A2) + (…) +
And then all of it over 100
Define element:
A substance which consists of only one type of atom
Define compound:
A compound is a substance that is made of two or more different elements which are chemically bonded together.
Define mixture:
A mixture is a substance that contains more than one type of atoms but there are no chemical bonds between the different parts of a mixture.
What is filtration?
Using filter paper to separate an insoluble solid from a liquid.
-it can be used in purification as well
What is crystallisation?
Crystallisation is used to separate a soluble solid from a solution
How do you crystallise a product?
- pour the solution into an evaporating basin
- slowly heat the solution and stop heating when crystals start to form
- leave the dish in a warm place for the rest of the solute to evaporate
- finally you’ve got the dry product, you can use a drying agent or a desiccator
What processes do you use to separate rock salt?
rock salt is a mixture of salt and sand
- grinding-grind up the rock salt with a pestle and mortar
- dissolving-dissolve in beaker and stir
- filtering-filter through filter paper in a funnel(removing the sand)
- crystallisation-evaporate in an evaporating dish(forming crystal salt)
How do you do paper chromatography?
How do you make a chromatogram
- draw a lesson near the bottom of a sheet of filter paper
- add dots of different dyes to the line at regular intervals
- put the sheet in a beaker of water
- make sure the dyes aren’t touching the solvent so they aren’t dissolved
- place a lid on the beaker to stop the solvent from evaporating
- the solvent seeps up the paper, carrying the dyes with it
- each dye will move up at different rates
- the end result is a pattern of spots called a chromatogram
How does chromatography separate mixtures?
- chromatography works because different dyes will move up the papers at different rates
- some will stick to the paper whereas others will dissolve more readily in the solvent and travel more quickly
- the distance the dyes travel depends on the solvent and paper you use
How can chromatography identify different dyes?
- you can work out the different dyes that are present in a substance by chromatography
- make a chromatogram for your unknown substance and reference materials(dyes that you think might be in that ink)
- then compare the chromatograms to work out what dyes are in the substance
From a chromatogram, how do you calculate the R🇫 value?
R🇫 value is the ratio between the distance travelled by the solute and the solvent
R🇫 = distance travelled by solute ÷ distance of solvent
What’s the use of simple distillation?
Used to separate out solutions
-separate a liquid from a solution
What’s the process of simple distillation?
- the solution is heated, the part of the solution with the lowest boiling point evaporates
- the vapour is then condensed and collected
- the rest of the solution is left behind in the flask
What can you use simple distillation for?
Can use it to get pure water from seawater
- the water evaporates and is condensed and collected
- you’ll eventually just be left with the salt and water separated
What’s a disadvantage of simple distillation?
- you can only use it separate things with very different boiling points
- you can separate out from a mixture with very similar boiling points
What’s fractional distillation used for?
Fractional distillation is used to separate a mixture of liquids
What’s the process of fractional distillation?
Using the example of the fractional distillation of crude oil at a refinery:
- put your mixture in a flask sticking a fractional column on top then heat it
- different liquids have different boiling points so they will evaporate at different times
- the liquid with the lowest boiling point evaporates first, and be the first to reach the top of the column
- liquids with higher boiling points might also start to evaporate but the column is cooler towards the top so they’ll condense and fall back down
- when the first liquid has been collected, you raise the temperature until the next one reaches the top
