Organic science Flashcards
Where are transition metals?
Between groups 2 and 3
What are properties of transition metals?
They form coloured compounds
Are generally (like all metals) hard, strong, shiny, malleable and conductive of heat/ electricity
They have high melting points (except mercury)
High DENSITIES
Properties of gold that make it useful for its purpose
Shiny, malleable, conductive of electricity and rust resistant so is used in electrical components.
Properties of copper that make it useful for its purpose
Malleable and corrosión resistant so is used in water pipes, is also a good conductor of electricity so can be used for electrical wiring.
Properties of iron that make it useful for its purpose
Is hard, tough, high density and so can be used for tools and building materials, is also malleable so can be used for car bodies
Is a catalyst in ammonia manufacturing
Titanium properties that make it suitable for its purpose
Is low density and high strength so can be used in fighter aircrafts, v resistant to corrosion so can be used in nuclear power pipes
Nickel properties suitable for use
Noncorrosive so can be used as coins
Which transition metals are used as catalysts?
Iron is used in the haber process in the production of ammonia.
Vanadium pentoxide is used for making sulphuric acid in the contact process.
Alloy
A mixture of 2 or more elements, one of which is a metal.
Why are regular metals not suitable for everyday uses?
The regular structure makes them soft as the layers can roll over one another.
Why are alloys stronger than normal metals?
Because the atoms of different sizes distorts the regular arrangement and so makes it harder for the atoms to slide over one another
What’s amalgam made up of and its use
Mercury (main metal) & is used in dental fillings
What’s brass made up of? Use?
Copper and zinc
Used for hinges and electrical plugs. (Where more friction is needed as is more malleable)
Solder use?
Lead and tin is used to join metals together
What are iron alloys called and made up of?
Steels, they are made by adding carbon (some other metals)
As steel is harder than iron, is less corrosive and so is used for bridges, engines, cutlery…
Bronze alloy and use
Copper and tin is used for medals and statues as is harder than copper
Gold alloy and use
Metals like zinc, copper, silver are used to strengthen gold. Can be used for jewellery
Aluminium alloys and use
Alloyed w small amounts of other metals to increase strength. Has low density and so can be used in aircrafts
Magnalium alloy and use
Aluminium and magnesium are mixed to make it stronger, lighter and less corrosive than aluminium. Is used for cars and aeroplanes .
High magnesium content is used for fireworks as is reactive and burns bright.
What type of reaction is corrosion of metals?
REDOX as the metal loses electrons (oxidised) while oxygen gains electrons (reduced)
What do metals corrode in the presence of?
Oxygen and water
Rusting
The corrosion of iron, (only in presence of oxygen and water)
Experiment to show that both oxygen and water are needed for iron to rust
1 put an iron nail in a boiling tube with just water (won’t rust). Boiling water beforehand will remove oxygen and oil can be used to stop air getting in.
2 put an iron nail in a tube w just air (won’t rust). Calcium chloride can absorb any water in the air.
3 put and iron nail in a boiling tube w air and water (will rust).
Ways to prevent rusting
Coating iron w a barrier, keeping water and oxygen out. Eg painting can cause a barrier.
On moving parts, oiling /greasing helps.
SACRIFICIAL protection involves placing a more reactive metal w the iron
Eg galvanising
What’s galvanising
Where a coat of zinc is put into an iron object to prevent rusting as zinc is more reactive and so will be oxidised easier and will corrode instead and acts as a barrier
Electroplating
Coating the surface of a metal with another metal using electrolysis
Process of electroplating
Cathode = object to electroplate
Anode = bar of metal to plate the object
Electrolyte = solution containing metal ions of the metal you are playing it with
The metal ions from the electrolyte move toward the cathode and is deposited on the object, the anode refills the metal ions in the solution
Homologous series
A group of chemicals that have the same functional group
Functional group
A group of atoms that determine how a molecule reacts.
Akkanes
A homologous series of saturated hydrocarbons
General formula of alkanes
CnH2n+2
First 4 alkanes
Methane, ethane, propane, butane
Number of bonds carbon atoms can make
4
Number of bonds hydrogen’s can make
1
Alkenes
A homologous series of unsaturated hydrocarbons containing a carbon-carbon double bond functional group
General formula of alkenes
CnH2n
First 3 alkenes
Ethene, propene, butene (but-1-ene, but-2-ene)
Test for alkenes
Shake the substance with bromine water and if it decolorises, it’s an alkene.
Why does bromine water turn clear in the presence of alkenes?
Because an addition reaction is taking place where bromine is added to the alkene double bond.
(Bromine is connected to the carbons)
Alkanes are saturated so this wouldn’t happen