C3 Flashcards
What are delocalised electrons?
Electrons which are able to move around
What are the properties of metallic bonding?
- Strong forces between metal ions
- Good conductors
- Solid
- Layers can slide off eachother
What do ionic equations show?
They show the useful parts of an equation
-cross out equations the same on both sides
What are displacement reactions?
More reactant metals displace less reactive metals
e.g.copper sulfate + iron>iron sulfate + copper
What happens when metals react with acids?
acid+metal>salt+hydrogen
The more reactive the metal, the faster the reaction will go.
What happens when metals react with water?
metal+water>metal hydroxide+hydrogen
-very reactive and low reactive metals won’t react with cold water
What is extracting metals with carbon?
Ores less reactive then carbon can be extracted by a displacement reaction
-During the reaction carbon is oxidised and the other metal is reduced
What is phytoextraction?
Growing plants in soil which contain metal compounds
-The plants can’t get rid of the compounds so they gradually build up in leaves
The plants can be burnt-the ash will contain metal compounds which can be extracted
What is bioleaching?
Using bacteria to convert insoluble compound in the ore to soluble compounds, seperating the metal and the ore
What is a redox reaction?
A reaction where electrons are transferred
What is ‘OIL RIG’
When dealing with electrons:
Oxidation
Is
Loss
Reduction
Is
Gain
What do half equations show?
Half equations show the movement of electrons
e.g Na > Na+ + e-
What is electrolysis?
During electrolysis, an electric current is passed through an electrolyte
The positive ions in the electrolyte move towards the cathode(-) and the negative ions move to the anode(+)
What possible reaction could occur at the cathode?
Pb(2+) + 2e(-) > Pb
What possible reaction could occur at the anode?
2Br(-) > Br2 +2e
When is electrolysis used?
When the metal is too reactive to be reduced with carbon
What happens at the cathode in an aqueous solution?
If H(+) ions and metal ions are present, hydrogen gas will be produced if the metal is more reactive than hydrogen If the metal is less reactive than hydrogen, the metal will be produced
What happens at the anode in an aqueous solution?
If there are chloride ions present, chlorine will be formed at the anode
If there are no chloride ions present, oxygen will be formed
What are covalent bonds?
When non metals bond together, they share pairs of electrons to make covalent bonds.
Each single covalent bond provides one extra electron for each atom.
What are the properties of simple covalent substances?
- Simple molecular substances
- strong covalent bonds
- weak forces
- weak intermolecular forces
- don’t conduct
What is the empirical formula?
The simplest ratio of atoms.
What is a homologous series?
A family of molecules which share the same general formulas and functional group.
-They share similar chemical properties.
What happens to properties as the carbon chain gets longer?
- The shorter the chain, the more runny they will be
- The shorter the chain, the lower the boiling point
What are Alkanes?
Homologous series. Alkanes are hydrocarbons Methane:CH4 Ethane:C2H6 Propane:C3C8 Butane:C4H10
What is fractional distillation?
Used to separate hydrocarbons
- Oil is heated to gas
- Fractional column has condensers
- Column is heated from the bottom so there is a temperature gradient
- The hydrocarbons have boiling points which condense back into liquids and drain out of the columns.
What are the uses of Crude Oil?
Provides fuel for transport
Making new compounds
Products like phones
What is the main problem with crude oil?
It is a non-renewable resource
-we have to continue developing new technologies.
What is cracking?
Splitting up long-chain hydrocarbons
-Hydrocarbons are heated until they become vapour which splits them up.`
What is a functional group?
A group of atoms within a molecule which determines how it reacts
All members are part of the same homologous group.
What is the main traits of alkenes?
They have a C-C double bond They have twice as many hydrogens as carbons Ethene Propene Butene Penetene
What are combustion reactions?
Carbohrydrate + oxygen>carbon dioxide+water
What are additional reactions? (alkenes)
e.g C2H4 + H2 >C2H6
Hydrogen can react with the double-bonded carbons to open the double bond and form an alkane.
e.g.C2H4 + Br2 > C2H4Br2
What is the alcohol functional group?
The O-H bond
e. g.mathanol:CH3OH
ethanol: C2H5OH
What are alcohols?
Industrial solvents that are able to dissolve in things water can’t.
What is the functional group of carboxylic acids?
They have the functional group COOH
e.g.HCOOH
CH3COOH