-It is an addition reaction -It splits the double carbon bond into a single one, becomes an alkane -Forms a colourless compound -Happens at room temperature
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What is hydrogenation?
-An addition reaction with an alkene and hydrogen -Splits the double carbon bond into a single one -known as hydrogenation -must take place at 60*c and in the presence of a nickel catalyst -Increases the molecules melting point
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How do alkenes combust?
-Burn with a yellow, smoky flame -Incomplete combustion is taking place -Creates less energy than when alkanes are burnt -Forms carbon dioxide and water
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Explain hydration, positives and negatives
-Water is added to ethene to create ethanol -100% atom economy -Crude oil (non-renewable) used to make ethene -Faster & more efficient -Catalyst: phosphoric acid -Requires lots of energy for steam & fractional distillation -Reversible reaction
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Explain fermentation, positives and negatives
-Glucose naturally forms ethanol and carbon dioxide -Very slow so not useful in industry -Catalyst: yeast -Carbon neutral -Renewable -Only needs to be heated to 37*, not much energy required -Uses sugar cane to create glucose
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How do alcohols combust?
-Burn with a clean(no soot), blue flame -Can be used as biofuels in cars -High flammability -Form carbon dioxide and water
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What does unsaturated mean, give some examples?
-Contains a carbon=carbon double or triple bond -It's not full of atoms Examples: Alkenes, esters, carboxylic acids
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How do alcohols react with sodium?
-Sodium reacts in a similar way to with water but less vigorously -Floats on the surface -Effervesces releasing hydrogen gas -Produces a sodium (alk)oxide
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Explain the difference between a strong and weak acid
-Strong acids undergo complete ionisation in solution -There is a higher concentration of H+ ions in a strongly acid solution -Therefore has a low ph of about 1 -Weak acids partially ionise in water as there is a lower concentration of H+ ions
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What is an addition reaction?
-It involves alkenes -The molecule reacting with the alkene will break open the double bond and 'add' to the alkene -This forms a saturated atom
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How are esters made and what are their uses?
By reacting a carboxylic acid with an alcohol, in the presence of a strongly acidic catalysts -They are volatile, fragrant compounds used in flavourings and perfumes
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What is the name of CH3COOH?
Ethanoic acid, you must include the carbon in the functional group when counting the number of carbons
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What are the properties of carboxylic acids?
-Usually have higher boiling points than water -Form acidic solutions when dissolved in water -Less acidic than hydrochloric acid, it is a weak acid -Has and unpleasant smells and taste -Not flammable -Forms salts when reacting with metal carbonates
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What is addition polymerisation?
-Usually needs high pressure and a catalyst -Uses the same repeated monomer to make the polymer -Monomer is unsaturated (alkene) -Only one product is formed, 100% atom economy -Double bond opens up
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What are the properties of alcohols
-Flammable -Undergo complete complete combustion forming carbon dioxide and water -Soluble in water, solutions have a neutral pH -When oxidised they form a carboxylic acid -They react similarly because they are in the same functional group
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What is condensation polymerisation?
-Creates two products: a polymer and small molecule(HCl or H20) -Different monomers are used to create the two products -Involves alcohols and carboxylic acids but each one requires two functional groups e.g ethandiol and ethandioc acid
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Give three examples of naturally occurring polymers and name their monomers
-An addition reaction with an alkene and hydrogen -Splits the double carbon bond into a single one -known as hydrogenation -must take place at 60*c and in the presence of a nickel catalyst -Increases the molecules melting point
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