Organic chemistry Flashcards
What are 4 organic compound groups
Alkenes
Alkanes
Alcohols
Carboxylic acid
What are hydrocarbons
Compounds contain only carbon and hydrogen
Definition of homologous series
used to describe compounds with similar structure and properties that can also be given a general formula
What is a functional group
An atom or group of atoms in a molecule does the term and chemical properties of a compound
What are the first five alkanes called
Methane ethane propane butane pentane
What is the difference between alkanes and alkenes
Alkanes do not have a double bond
What is the formula for an alkane
N = carbons
CH2n+2
What does saturated mean
Saturated hydrocarbon is a hydrocarbon with only single bonds between the carbons
What does unsaturated mean
An unsaturated hydrocarbon is a hydrocarbon with one or more double bonds between carbon atoms
What are the first five alkenes
Ethene propene butene pentene hexene
Why do you not have an alkene called methene
Because if it only has one carbon atom it cannot have a double bond to another carbon atom so it won’t work
What is the general formula for alkenes
CH2n
What is crude oil
Is a fossil fuel that comes directly from the earths crust and is one of the most important substances in the world crude oil is a complex mixture of hundreds of compounds
How can you separate the compounds in crude oil
By fractional distillation
What is crude oil used for
Transport heating and generating electricity it can also be used to make plastics
How is crude oil formed
It is formed over millions of years is formed from the remains of many tiny sea animals and plants called plankton
Where is crude oil found
Found traps in sedimentary rocks under the sea bed oil rigs are used to obtain the oil
What is fractional distillation
Fractional distillation is a process used to separate a mixture of liquids have different boiling points when the mixture is heated liquids with a low boiling point will evaporate and turn to vapour liquid with higher boiling points remain as liquid vapour than can be separated from the liquid
How is crude oil separated into fractions
Oil is heated to about 370°C and pumped into the bottom of the tall tower called a fractionating column where it vaporisers
The column is very hot at the bottom but much cooler at the shop as the vaporised oil rises it cools and condenses heavy fractions how high boiling points and condenser near the bottom of the column lighter fractions have lower boiling points and condense further up the column
How old are hydrocarbons in different fractions differ from each other
The number of carbon and hydrogen atoms they contain
The boiling point
Ease of ignition
Viscosity
How does the size of the crude oil atom affect its boiling point
Generally the larger a hydrocarbon the higher is boiling points this is because the intermolecular forces between large molecules are stronger than the intermolecular forces between smaller molecules
What is the equation for combustion
Fuel and oxygen turns into carbon oxide and water
Definition of combustion
The scientific word for burning it is a rapid reaction between a substance and oxygen that releases heat and light
What is complete combustion
It means there is enough oxygen available for all of the carbon atoms in a fuel suborn and form carbon dioxide
What is used to test for carbon dioxide gas
Lime water if carbon dioxide gas is bubbled through limewater it goes cloudy
What does incomplete combustion produce
Carbon monoxide
What is incomplete combustion
Where there is not enough oxygen to get rid of all the carbon so it falls carbon monoxide
How do you know if combustion or incomplete combustion is happening
If complete combustion is happening the flame will be bright blue if incomplete combustion is happening it will be yellow
Why is carbon monoxide hard to detect
Because it is colourless odourless and very toxic
How does carbon monoxide kill
It reduces the ability of the blood to carry oxygen by attaching itself to red blood cells instead of haemoglobin
What is prevents CO from coming out at the back of a car
Catalytic converters the convert of the CO into CO2
How was soot produced
What amount of oxygen available is very limited incomplete combustion can also produce carbon particulates often refer to a suit
What gases are in the early atmosphere
Carbon dioxide methane water vapour and ammonia
How much nitrogen oxygen argon in carbon outside this earth of today
Nitrogen – 78%
Oxygen – 21%
Argon – 0.9%
Carbon dioxide – 0.037%
How have the levels of gases in the atmosphere changed over time
Volcanoes release carbon dioxide and water vapour water vapour condenses to form oceans carbon dioxide dissolves into the ocean photosynthesis by Primitive plants produce oxygen levels of carbon oxide decrease and levels of oxygen increase in the earths atmosphere
How is carbon oxide decreased in the office atmosphere
Photosynthesis
Absorbed into rocks
Absorbed by the ocean
How does heat travel from the Sun to earth
By radiation
What is the greenhouse effect
Greenhouse gases let the suns light shine country of surface but they trap the heat reflects back up onto the atmosphere and increases the temperature of the earths atmosphere
What are the main greenhouse gases
Carbon dioxide methane water vapour
What does shortwave radiation and longwave radiation do you
Short wave radiation passes through the atmosphere longwave solar radiation is reflected back by the Earth some longwave radiation is absorbed in remission by greenhouse molecules in the atmosphere this warns the Earth surface and lowers the atmosphere
Why are greenhouse gases bad for the Earth
The Earth is heated by the Sun
Not all the energy reaching the Earth warms up the planet 30% is reflected back into space greenhouse gases let UV light pass through the surface of the Earth cools down at night by admitting IR radiation but Greenhouse gases when dissolved I are making the bonds bend and stretch and vibrate more vigourously raising the temperature this energy is trapped in the atmosphere causing the temperature to rise
How is methane produced
Through agriculture and decomposition of rubbish and landfill sites
How is CO2 produced
Fossil fuels
Deforestation
What happens when we burn fossil fuels
The carbon outside has been buried for hundreds of millions of years is released into the atmosphere
Why are greenhouse gases important to life on Earth
Because he wouldn’t be able to grow crops at a temperature of -19 which is what it would be without them
What are some affects of climate change
Polar ice caps melting sea levels rising
Extinction of species living in cold climates
Changes of rainfall
Changes in species distribution
What can changing weather patterns all over the world resultant
Rising sea levels
Increase in frequent extreme weather events
Changes in rainfall
Changes in disruption wildlife
What is carbon capture
Pump CO2 underground into oil reservoir and lock it in with concrete
Definition of carbon capture
Take in carbon dioxide from an industrial process and depositing it into underground rocks to prevent a entering the atmosphere
Definition of carbon footprint
The total amount of carbon dioxide and other greenhouse gases produced over the full life-cycle of a product service or event
Definition of carbon neutral
Any process that has no overall release of carbon oxide by balancing the amount of carbon dioxide released with the amount taken in
What is the definition of carbon offsetting
Carrying out activities that will increase the natural rate of removal of CO2 from the atmosphere such as reforestation and treeplanting
How is acid rain made
Sulphur and nitrogen impurities in fossil fuels
Sulphur dioxide and nitrogen oxides released when burned
Dissolves in water vapour of clouds to form sulphurous and nitrous acids
Falls is acid rain less than pH 5.5
What produces sulphur dioxide
Call contain sulphur therefore the burning of coal and oxygen produces sulphur dioxide. This leads to acid rain
What produces nitrogen
Nitrogen oxides formed due to the reaction between nitrogen and oxygen in the air one on the hyper temperatures this often happens in car engines due to the heat from combustion of petrol this can lead to acid rain in global dimming
How is carbon monoxide formed
Carbon monoxide forms when there is not enough oxygen available for a fuel burning instead of forming carbon dioxide and water carbon deposits and carbon monoxide are formed this can lead to carbon monoxide poisoning
How can you reduce sulphur dioxide
To reduce the amount of sulphur dioxide produced from combustion of fossil fuels we can react sulphur Darkside with powdered limestone to form calcium sulphate this can be used to make plasterboard for lining interior walls
How can you reduce nitrogen oxide
To reduce levels of nitrogen oxides released from cars and catalytic converter can be fitted which reduces nitrogen oxides to nitrogen
How can CO be reduced
To reduce levels of carbon monoxide a catalytic converter can be fitted which oxidise is carbon monoxide to carbon dioxide
What is catalytic cracking an example of
Thermal decomposition reaction
What is catalytic cracking
Long chain hydrocarbon molecules can be broken down into smaller more useful molecules using a catalyst
What conditions are required for catalytic cracking
High temperatures E.g 500°C
A catalyst aluminium oxide
What happens during cracking
During cracking the molecules break apart forming smaller alkanes and alkenes alkenes are unreactive molecules that are used to make plastics and other chemicals
What are the products of catalytic cracking
Smaller alkanes and alkenes
How do you distinguish between saturated and unsaturated compounds
Add orange bromine water in the presence of unsaturated compound to orange colour disappears
How do you test for alkenes
Add bromine water to the Alkim and it should go colourless if it is an Alkene
Definition of polymers
Very large molecules made one hundreds of monomers join together to form long chains
Definition of monomers
Small identical molecules to form long chains
What is addition polymerisation
It is a reaction where lots of alkene molecules join together to form a long chain polymer
What are the monomers and polymers join together bye
Covalent bonds
How can you show polymers in a shorthand formula
Draw one repeat of the polymer and put brackets around it and put n at the bottom right to show how many more it needs One bracket is a repeating unit
What are the properties of polymers
The atoms in a polymer chain are linked together by strong covalent bonds the forces between polymer molecules are weaker polymer chains can move over each other so the polymer can be stretched
