Hydrocarbons and Organic compounds Flashcards
Hydrocarbons are:
a group of compounds that contain the elements Hydrogen and Carbon compounds that contain only carbon atoms and hydrogen atoms obtained from crude oil by fractional distillation and can be classified into different groups. The three groups that you need to know about for Standard Grade are called alkanes, alkenes and cycloalkanes.
what are alkanes and give 4 examples What is the general formula for calculating number of H atoms
Alkanes are a group of compounds that contain only single (covalent bonds) between atoms of carbon or between atoms of carbon and atoms of hydrogen. ( all numbers should be small and beneath line ) Simplist first;,
Methane CH4.
Ethane, C2H6.
Propane C3 H8
Butane C4H10
To find the number of H atoms, simply double the number of C atoms and add two. We say that the general formula of alkanes is CnH2n+2.
Properties of Alkanes
1, Alkanes are called SATURATED hydrocarbons because they only have single bonds between carbon atoms. 2. Alkanes combust in a plentiful supply of air to release energy (this is why they are used as fuels). 3.Combustion also produces carbon dioxide and water vapour 4. If the oxygen supply is restricted - meaning that there’s not enough air - then the combustion of alkanes produces the poisonous gas carbon monoxide.
What are Alkenes and give examples. What is the general formula for calculating number of H atoms
hydrocarbons but they contain a double bond between two adjacent carbon atoms.
The simplest alkene is Ethylene C2H4.
Propene, C3H6 .
Butylenes C4H8
Alkenes have a general formula. To find the number of H atoms, simply double the number of C atoms. We say that the general formula of alkanes is CnH2n.
Properties of Alkenes
Alkenes are said to be UNsaturated Hydrcarbons because of the carbon-to-carbon double bond in their structure Alkenes undergo combustion in a similar way to alkanes. They also undergo many other chemical reactions that alkanes do not - the double bond in alkenes makes them more reactive than alkanes. Forexample, bromine can be added to the alkene double bond. This is called an addition reaction - a typical addition reaction occurs with bromine. The reaction makes the reddish brown colour of ‘bromine solution’ disappear.
What is a covalent bond
A covalent bond is a shared pair of electrons between two non-metals. Very strong
All hydrocarbons have a common namimg or Nomenclature
Alkanes are named by using the prefixes shown and adding the suffix “-ane”. All alkanes have an “-ane” ending. All alkenes end in “-ene.” You must be able to list the names of the first 6 alkenes. Cycloalkanes are named by using the prefix “cyclo-” in front of the corresponding alkane.
The full structural formula and chemical formula of
Methane
Alkanane methane, formula CH4. The full structural formula is shown above.
structure of Ethane
full structure formula of Propane
propane alkane C3H8
Full structure and chemical formula for Ethane which is a ….
The simplest alkene is ethene, C2H4. It has this structural formula.
full structure formula and chemical formula for Propene
alkene is propene, C3H6 . It has this structural formula.
Properties of Methane
At room temperature and standard pressure, methane is a colorless, odorless gas.[8] The familiar smell of natural gas as used in homes is a safety measure achieved by the addition of an odorant.
Methane has a boiling point of −161 °C (−257.8 °F) at a pressure of one atmosphere.[9]
As a gas it is flammable only over a narrow range of concentrations (5–15%) in air.
Liquid methane does not burn unless subjected to high pressure
Lighter than air
main component of natural gas
Properties of Ethane
Ethane is a chemical compound with chemical formula C2H6. At standard temperature and pressure, ethane is a colorless, odorless gas.
Ethane is isolated on an industrial scale from natural gas, and as a byproduct of petroleum refining.
At room temperature, ethane is a flammable gas.
When mixed with air at 3.0%–12.5% by volume, it forms an explosive mixture.
Direct contact with liquid ethane can result in severe frostbite.
In addition, the vapors evaporating from liquid ethane are, until they warm to room temperature, heavier than air and can creep along the ground or gather in low places, and if they encounter an ignition source, can flash back to the body of ethane from which they evaporated.
Properties of Propane
Unlike natural gas, propane is heavier than air (1.5 times as dense)
Propane is nontoxic; poses a mild asphyxiation risk through oxygen deprivation.
gas at room temp and room pressure
highly flammable
odourless ( stenching agent added )
colourless
above 96.7 degrees C can ONLY EXIST AS A GAS
flammable range 2.4to 9.5
self ignite 538 degrees c
