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40 Cards in this Set
- Front
- Back
What is the main feature of an organic compound |
CARBON |
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Anything that ONLY contains carbon and hydrogen is called.... |
A hydrocarbon |
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Define saturated and unsaturated in terms of hydrocarbons |
Saturated- No double bonds. Every carbon has the maximum number of hydrogens Unsaturated- One or more double bonds, the hydrocarbon does not contain the maximum number of hydrogens |
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Give the structural formula of 3-methylpentan-1-ol |
Structural: CH3CH2CH(CH3)CH2CH2OH |
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Define Functional group and give 4 examples of functional groups |
An atom or group of atoms in a molecule that is responsible for its chemical reactions and predictable properties E.g. Aldehydes Carboxylic acids Ketones Alcohols Amines Alkane Alkene |
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Define Homologous series |
Compounds with the same functional group, which differ by a CH2, with similar chemical and physical properties, that show graduation |
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What are the types of structural isomerism? |
Chain isomerism Positional isomerism (Functional group isomerism?) |
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What is stereoisomerism? |
Stereoisomers have the same molecular formula and same structural formula but with a different arrangement of atoms in space (three dimensions) |
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Geometric isomers (e/z) are a type of ......... |
stereo isomer |
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Describe the process of Fractional Distillation |
Crude oil is the feed stock. It is heated in a furnace There is a temperature gradient through the column- hotter near the top, cooler near the bottom Different fractions condense at different temperatures/heights in the column Bigger/longer chain molecules are at the bottom. Shorter/smaller molecules are at the top. Each fraction still contains a few compounds so go through further distillation separately |
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Describe the process of cracking and why it is useful |
There are fewer uses for long chain hydrocarbons, so excess of these can be 'cracked' into shorter ones. The process: Pass the long hydrocarbons over a heated Zeolite catalyst Forms an alkane and an alkene |
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Describe why the process of reforming is useful and give an example of it happening: pentane into a cycloalkane |
Straight chain hydrocarbons burn less efficiently/smoothly than branched and cyclical ones. (e.g. in car engines) The process: Pentane -------> cyclopentane + H2 |
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Define: Fractional distillation Cracking Reforming |
Fractional distillation- The process used to separate a liquid into fractions by boiling and condensing Cracking- The breakdown of molecules into shorter ones by heating with a catalyst Reforming- The conversion of straight chain hydrocarbons into branched-chain and cyclic hydrocarbons |
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Briefly describe where we can get biodiesel and bioalcohols (bioethanol in particular) from, and give a reason why using these sources could have a negative impact |
Biodiesel- Starting material from rapeseed and sunflowers Bipethanol- produced using bacteria rather than enzymes. This means a wider range of plants can be used and the amount of ethanol obtained from the plants is higher. In the US, corn is the main source of ethanol used in cars. Some people think this is bad as it could be being used to feed people |
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What factors must you consider when comparing or assessing a biofuel? |
Land use Yield Manufacture and transport Carbon neutrality |
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What does 'Carbon Neutral' mean? |
Resulting in no net release of carbon dioxide into the atmosphere |
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How do you get ethanol from petroleum? |
Petroleum | |Fractional distilation and cracking V Ethene | |Hydration V Ethanol |
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How can you make ethanol renewably |
Starch | | V Glucose | |Fermentation V Ethanol |
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The chlorination of methane is done through what mechanism? Write the stages and equations |
Free radical substitutuion Initiation: Cl2 ------> 2Cl* Propagation: Cl* + CH4 ----> CH3* + HCl CH3* + Cl2 ------> CH3Cl + Cl* Termination: 2Cl* -----> Cl2 CH3* + CH3* -----> C2H6 CH3* + Cl* ----> CH3Cl |
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What is a radical |
An atom or molecule with an unpaired electron |
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What condition is required for initiation of free radical substitution? |
UV Light |
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Radicals are formed via ................ of a covalent bond |
Homolytic fission |
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Define mechanism |
A sequence of steps in an over all reaction. |
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An addition reaction involves breaking a ........... bond, and forms a ........... product |
Pi Saturated |
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Hydrogenation is a type of .......... reaction and is done with a ................ catalyst |
Addition Nickel |
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Halogenation is type of .......... reaction. The mechanism used is..... |
Addition Electrophilic addition |
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The intermediates formed in addition reaction of alkenes are called ............... |
Carbocationsl |
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Hydration of alkenes is done by reacting the alkene with ............ over a ..................... catalyst |
Steam Phosphoric acid (H3PO4) |
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What reaction can you use to test for a C=C? |
Addition of bromine (bromine water) Brown to colourless (electrophilic addition) |
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Hydration of alkenes forms ......... |
Alcohols |
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Define an electrophile |
A species that is attracted to regions of high electron density |
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Why can more than one product be formed in some addition reactions? |
Because more than one type of carbocation can form (primary, secondary, tertiary) |
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Which type of carbocation (primary , secondary, tertiary) is most likely to form and why? |
Tertiary - This is the most stable (the positive charge is more spread) so forms more readily |
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Enthalpy is.... |
the measure of the total energy in a system |
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When energy is transferred from the system to the surrounding the reaction is ........ |
Exothermic |
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When energy is transferred from the surroundings to the system the reaction is ........ |
endothermic |
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Define the standard enthalpy change of combustion |
The enthalpy change when one mole of a substance is completely burned in oxygen, under standard conditions |
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Define the standard enthalpy change of formation |
The enthalpy change when one mole of a substance is formed from its constituent elements in their standard states, under standard conditions |
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Define standard enthalpy change of neutralisation |
The enthalpy change when one mole of water is produced by the neutralisation of an acid and alkali |
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Define bond enthalpy |
The enthalpy change when one mole of a bond is broken is the gaseous |