Easter Test Flashcards
Saturated
A hydrocarbon with only single bonds between its atoms. This means that it contains as many hydrogen atoms as possible in each molecule eg an alkane
Unsaturated
A hydrocarbon whose molecules contain at least one carbon-atom double bond eg. An alkene
Alkane
Saturated hydrocarbon with the formula of CnH2n+2
Alkene
An unsaturated hydrocarbon which contains a carbon-carbon double bond. It generally formula is CnH2n
Hydrocarbon
A compound containing only hydrogen and carbon
Molecular formula
The total number of atoms of each element in a molecule
Structural formula
Shows the arrangement of atoms in a molecule
Displayed formula
Shows how the atoms and bonds in a molecule are arranged
Homologous series
A group of chemicals (eg alkanes) which have similar chemical properties and can be represented as general formula
Explain the process of fractional distillation
The crude oil is heated until vaporised, these vapours move up the fractioning column the further up the column the cooler it becomes. As the gasses move up the fractioning column they cool down, as each fraction condenses at a different temperature they are collected at different points, each fraction contains hydrocarbons with a similar number of carbon atoms. The refinery gasses have very low boiling points and do not condense and pass out the top of the fractioning column, longer chained hydrocarbons such as bitumen have higher boiling points and collected towards the bottom of the column whereas shorter chained hydrocarbons like petrol are collected near the top.
Wh do long chained hydrocarbons have high boiling points
The intermolecular forces between large molecules are stronger than the intermolecular forces between small molecules. More energy is needed to break the forces between the large molecules, and so the boiling point is higher.
First four Alkenes
Methane,ethane,propane,butane
What are the 2 conditions for cracking
High temperature, a catalyst
Describe the process for cracking
The paraffin is heated until vapourised/ evaporated, the broken porcelain or aluminium oxide acts as a catalyst. The paraffin is cracked into smaller chained hydrocarbons and an alkane and an alkene are produced
What is the test for alkane/ alkenes
Bromine water
Alkane + bromine water=no reaction & solution stays orange
Alkene + bromine water=reaction & solution turns colourless
Equation for complete combustion
Hydrocarbons + oxygen —> carbon dioxide+ water
Equation for incomplete combustion
Hydrocarbon + oxygen —> carbon monoxide + carbon + water
Equation for incomplete combustion when there is not enough oxygen to produce monoxide
Hydrocarbon + oxygen —> carbon + water
What is mass number
The mass number of an atom is its total number of protons and neutrons and is always the bigger number
How do u find out how many neutrons there are
Number of neutrons = mass number- atomic number
What is atomic number
Number of protons / electrons ( smaller number )
What does the aq state symbol mean
aqueous (dissolved in water)
Where is proton found and what is its relative charge and mass
Found in the nucleus
Relative mass = 1
Relative charge = +1
where is neutron found and what is its relative charge and mass
Found in nucleus
Relative mass = 1
Relative charge = 0
Where is electron found and what is its relative mass and charge
Found in shells
Relative mass = 0
Relative charge = -1
What are ions
Electrically charged particles formed when atoms lose or gain electrons
What happens to non metals in chemical reactions
Gain electrons and become negative
What happens to metals during chemical reactions
Lose electrons and become positive
What is an ionic bond
The metal atoms become positive ions and the non-metal atoms become negative ions. There is a strong electrostatic force of attraction between these oppositely charged ions – this is called an ionic bond, it is between a metal and non metal.
What is covalent bonding
When 2 or more atoms bond by sharing electrons normally occurring between non metal atoms.the atoms in the molecule are held together strongly but there are weak forces between individual molecules, so have low melting and boiling points and are usually liquids or gasses
What is metallic bonding
Metallic bonding is the electrostatic attraction between positive metal ions and delocalised electrons. The organisation of the metal ions and the free-moving electrons give metals certain properties, such as malleability and ability to conduct heat and electricity, between 2 metals.
Why does metal conduct electricity
There are delocalised electrons which carry charge through the structure
How are metals arranged
In a lattice pattern of positive metal ions in a sea of negative delocalised electrons
Reactivity series
Please - potassium
Stop - sodium
Calling - calcium
Me - magnesium
A - aluminium
Careless - carbon
Zebra - zinc
Instead -iron
Try - tin
Learning - lead
How - hydrogen
Copper
Saved - silver
Gold
General equation for reaction between metals and oxygen
Metal + oxygen —> metal oxide
What is a displacement reaction
A more reactive element displaces (kick out) the less reactive element from the compound after the reaction the less reactive element is now left pure and uncombined
Eg. Cucl2 + mg = mgcl2 + cu
What is oxidation
The addition of oxygen Or the removal of electrons.
What is reduction
Removal of oxygen or the addition of electrons
What is a metal ore
A rock that contains enough of a metal or metal compound to make it worth extracting the metal
How do you extract metals
If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.
However if the metal is more reactive we use electrolysis,electrolysis involves using electricity to break down electrolytes to form elements
