Organjc Chemistry Part 2 Flashcards
What is the general formula of an alcohol
CnH2n+1OH
What are the three ways that you can oxidize ethanol
By combustion
By microbial/aerobic oxidation
With an oxidizing agent (like potassium dichromate (IV) in sulfuric acid)
Give the word equation of the combustion of ethanol
Ethanol + oxygen —-) carbon dioxide + water
Give the balanced symbol equation of the combustion of ethanol
C2H5OH(l) + 3O2(g) ——) 2CO2(g) + 3H2O(l)
What type of fuel is ethanol and what are examples of what it is made of
A biofuel
Made of for example corn or sugar cane
Explain why wine has a sour taste after a few days of being open
Microorganisms in the wine use the oxygen in the atmosphere
to oxidize the ethanol
Into ethanoic acid
Where the acid gives the wine it’s sour taste
Which oxidizing agent can be used to form ethanoic acid, from ethanol
potassium dichromate (IV) acidified in dilute sulfuric acid
Give the symbol equation of potassium dichromate (IV)
K2Cr2O7
State what is oxidized and what is reduced in the oxidation reaction of ethanol using an oxidizing agent
Ethanol is oxidized
Potassium dichromate is reduced
When ethanol is oxidized using an oxidizing agent, state what the colour change is and why
Orange to green
And is Green because of the presence of Cr^3+ions
Give the oxidation equation of ethanol being oxidized using an oxidizing agent
CH3CH2OH + 2[O] ——) CH3COOH + H2O
(Always use the structural formula to show alcohols)
One way to set up the experiment for oxidizing ethanol with an oxidizing agent is to use a vertical condensing jacket in top of a flask. Explain why the condensing jacket is there
Because some of the volatile components of the ethanol may evaporate quickly,
So the condensing jacket condensed this back into a liquid so that the solution can boil for longer
How would éthanol production be affected if sugar and yeast were left in an environment with oxygen
Ethanol would not be produced because instead, the yeast would respire aerobically
And would produce carbon dioxide and water instead
Or then the oxygen would react with the ethanol produced to make ethanoic acid, giving the drink a sour taste
What are the two ways that ethanol can be produced
By fermentation
Or hydration of ethene
Give the word equation to produce ethanol from fermantion
Glucose—-(yeast)—) ethanol + carbon dioxide
Give the balanced symbol equation to produce ethanol from fermentation
C6H12O6—-(yeast)——-) 2C2H5OH + 2CO2
Explain how to produce ethanol from fermentation (5)
1)place sugar/starch in water and then add yeast
2)heat to 30 degrees and make conditions anaerobic
3)the enzymes in the yeast will ferment the sugars , to produce ethanol and carbon dioxide
4) when ethanol concentration reaches 15% the yeast is killed, so vessel should be emptied for a new batch
5) the ethanol produced needs to be fractionally distilled to produce a pure sample
Why can alcoholic drinks never have more than 15% alcohol concentration
Because when the ethanol produced in the fermentation process reaches 15% concatenation it kills the yeast, and so the sugar can no longer be broken down to produce ethanol
What is the temperature and catalyst used to produce ethanol from fermentation
30 degrees temperature
And
Enzymes in the yeast
Give the balanced symbol equation to produce ethanol from the hydration of ethene
(In terms of molecular formula)
C2H4(g) + H2O(g) —-) C2H5OH(l)
What type of reaction is the hydration of ethene and why
Addition, because atoms are being added, and none are being removed
Give the balanced symbol equation of producing ethanol from the hydration of ethene
(In terms of structural formula)
CH2=CH2 (g) + H2O (g)—-) CH3CH2OH(l)
Explain Why may you have to use fractional distillation after carrying out the hydration of ethene to produce ethanol
Because the process produces ethanol, water and unreacted ethene
So fractional distillation is used to take a pure sample of ethanol
Which takes advantage of how ethene has a much lower boiling point than both water and ethanol
What is the temperature,
catalyst,
And pressure used, when carrying out the hydration of ethene
Temperature is 300 degrees
Catalyst is phosphoric acid
Pressure is 60-70 atmospheric pressure
Give two advantages of producing ethanol from hydration of ethene
Has a higher yield, because is more efficient
Much quicker process
Why does producing ethanol from fermentation give a low yield
Because it is inefficient
As in the batch process that is used, products may be wasted
Give two disadvantages of producing ethanol from hydration of ethene
-Requires large amounts of energy
-non renewable and finite resource (because ethene comes from crude oil)
What is vinegar
An aqeous solution of ethanoic acid
Complete the word equation:
Aqueous Ethanoic acid + magnesium
—-) magnesium ethanoate + hydrogen
Complete the word equation:
Sodium carbonate + aqeous ethanoic acid —-)
—-) sodium ethanoate + carbon dioxide + water
(Because when a metal reacts with an acid a salt, co2 and H2O is formed)
What kind of acids are Carboxylic acids and what PH do they usually have
Weak acids,
With PH 3-5
Will metals below hydrogen react with ethanoic acid and explain why
No
Because they are unreactive
What could you observe happening in the reaction between zinc and aqeous ethanoic acid
Bubbles would be formed (but slowly)
Write the balanced symbol equation with state symbols of the reaction between magnesium and ethanoic acid
Mg(s) + 2CH3COOH(aq) —-) (CH3COO)2Mg(aq) + H2(g)
(-Remember to get the ionic equation of magnesium ethanoate right
-rmeber to write the magnesium after the ethanoate
-remeber to balance the equation
-remeber the state symbols and that the ethanoic acid and magnesium ethanoic will be aqeous)
What colour is the solution of magnesium ethanoate formed from magnesium + aqeous ethanoic acid, and explain why
Colourless
Because the magnesium ethanoate is soluble in water
Write the balanced symbol equation of sodium carbonate and ethanoic acid
Na2CO3(s) + 2CH3COOH(aq)—-) 2CH3COONa(aq) + CO2(g) + H2O(l)
(-Remember to get the ionic equations right
-rmeber to write the sodium after the ethanoate
-remeber to balance the equation
-remeber the state symbols and that the ethanoic acid and sodium ethanoate will be aqeous)
Write the balanced symbol equation for calcium carbonate + ethanoic acid
2CHCOOH(aq) + CaCO3(s) —-) (CH3COO) 2Ca(ag) + CO2(g) + H2O(l)
Give the structural formula of ethanoic acid
CH3COOH
Give the structural formula of butanoic acid
CH3CH2CH2COOH
Give the structural formula of methanol acid
HCOOH
Write the general equation to make an ester
Alcohol + Carboxylic acid —-) ester + water
Write the balanced symbol equation with state symbols for the production of ethyl ethanoate
CH3CH2OH(l) + CH3COOH(l) ——) (——- CH3COOCH2CH3(l) + H2O(l)
(Remember the reversible sign inbetween)
Give two things esters can be used for
Perfumes
Food flavorings
Give two properties of esters that make them usueful for perfumes
Pleasant scents
Volatile (so evaporate easily)
Give two names for the name of the reaction to make ethyl ethanoate
Estérification
And condensation
Name the alcohol and Carboxylic acid used in methyl methanoate
Methanol is the alcohol
Methanoic acid is the Carboxylic acid used
Explain why a Bunsen burner is not suitable to use in an experiment to make an ester
Because the contents are highly flammable
Explain why once an ester is made why is it often poured into a sodium carbonate solution
So that the excess acid can react with the sodium carbonate, so that the smell of the ester is stronger
(Because the Carboxylic acid masks the smell of the ester)
An ester is made, and is then poured into a solution of sodium carbonate. Explain what will happen to the ester now and the excess Carboxylic acid and alcohol
The ester will float in the top and the Carboxylic acid and alcohol will dissolve into the water
What is the catalyst used in the reaction to make ethyl ethanoate
Dilute sulfuric acid
What is the name of the solution that an ester can be poured into to make it a stronger smell
Sodium carbonate solution
What is a polymer
A LONG CHAIN made by JOINING many smaller molecules together
What is the monomer used to produce poly(butene)
Butene monomers
What is the molecular formula of poly(propene)
(C3H6)n
(Remember that for polymers you always need to write an “n” next to the formula of the monomer)
Are polymers saturated or unsaturated and explain why
Saturated because they contain no double bonds
What are the three things required for an addition polymérisation reaction to occur
Heat
High pressures
And an initiator
How does an initiator differ from a catalyst
An initiator is consumed in the reaction ,whereas a catalyst is not
What is an initiator
Starts the process of for example an addition polymerization reaction
What colour is bromine water if poly(ethene) is added to it and explain why
It does not decolorize so stays orange,
Because poly(ethene) is a polymer which are Alkanes
and alkanes do not undergo reactions in bromine water
Give a property or poly(propene)
Strong and rigid
Give a property of poly(ethene)
Flexible and strong
Give two examples of things made of poly(ethene)
Plastic bags
Storage bottles for food
Give two examples of things made of poly(propene)
Ropes
Crates
Give two properties or poly(chloroethene)
Strong and does not conduct electricity
Give three examples of poly(chloroethene)
Water pipes
floor coverings
or Used for electrical insulation
What is another name for poly(chloroethene)
PVC
Give two properties of poly(tetrafluroethene)
unreactive
Slippery
Give two examples of things made of poly(tetrafluroethene)
Non-stick coating for pots and pans
Liner for containers of corrosive chemicals
Write the repeating unit of poly(propene)
Check your book
(Make sure you have a CH3 group
Make sure you have only single bonds
Make sure you have a bracket with an N
Make sure you have bonds sticking out)
Give two advantages of landfill sites
They are cheap
They release no greenhouse gases from plastics
Give two advantages of incineration
-does not use a lot of space
-can generate heat or electricity for local homes
Give three disadvantages of landfill sites
-uses up a lot of space
-smells and is unpleasant to look at
-waste remains for thousands of years
Give three disadvantages of incineration
-releases greenhouse gases
-ash produced still needs to be disposed of in landfill sites
-expensive to build and maintain
What is condensation polymérisation
When monomers join together and a small molecule is eliminated/lost as a by product, which is usually water
Give an example of a type of substance created from condensation polymérisation
A polyester
Which two substances are required for a polyester to form
A dicarboxylic acid monomer and a diol monomer
What are two conditions required for a condensation polymérisation reaction to occur
-each monomer should have atleast two functional groups
-and there should be atleast two different functional groups present overall
Give an example of an equation to form a polyester
Ethanedioc acid + ethane-1,2-diol ——) poly(ethyl ethanoate) + water
Write the structural equation to make poly( ethyl ethanoate)
Look in your book
Give an example of a substance that is used to make a biodegradable polyester
Lactic acid
During condensation polymérisation, a Carboxylic acid joins with an alcohol to create…
An ester link
What does biodegradable mean
When a substance can be BROKEN DOWN naturally by BACTERIA
What is the functional group of an ester
-COO
How can an alcohol be removed form an impure ester
Add calcium chloride
Describe how to carry out simple distillation to prepare a sample of an ester
1)Heat the Carboxylic acid, the alcohol and sulfuric acid In a round bottomed flask using a water bath, but not a Bunsen burner because the contents are highly volatile
2)the ester will quickly evaporate because it has a low boiling point, and then will be condensed and collected in the beaker
3)calcium chloride can be added then to remove the alcohol and sodium carbonate can be added to remove acidic impurities
After preparing an esteem how can u test ti be certain if an ester has been made
It can me smelt by wafting it towards you because esters have strong and pleasant smells
Can alkanes be used for polymérisation?
No because they are saturated and polymérisation requires the presence of the double bond
What property of polymers makes them non biodegradable
They are inert
(Because they have such strong covalent bonds that there would be so much energy required to break them)
State two changes that occur in the formation of an addition polymer from its monomer
-the double bond becomes a single bond
-the chain length increases
Give two advantages of producing ethanol with hydration of ethen rather than by fermentation
-faster rate of reaction
-a continuous process so more efficient
Explain why some countries may use fermentation rather than hydration of ethene to produce ethanol
Because they have a suitable environment for growing sugar cane
What type of reaction is this:
C2H5OH—-) C2H4 + O2
Dehydration
(Because it’s the opposite of hydration)
What is the general name for compounds such as sucrose and glucose
Sugars
How is carbon monoxide dangerous to humans(2)
It reduces the ability of the blood to carry oxygen
And so can cause death
Describe, in terms of structure and bonding, what happens when
chloroethene molecules are converted into poly(chloroethene).
Any three from:
M1 - (one bond in the) double bond breaks
M2 - small molecules/monomers/chloroethene
molecules join together
M3 - to form a (long) chain/macromolecule
M4 - product/polymer contains only single bonds
State what is meant by dehydration
The removal of water
State how you would know that the reaction between glucose and yeast has finished
There would be no more bubbling
What is the reaction of ethanol to ethene called
Dehydration
Give an example of a polymer formed by condensation polymérisation
Nylon
Describe how covalent bonds differ in crude oil compared to kerosene
There are more covalent bonds in crude oil than in kerosene
Give two differences between condensation polymérisation and addition polymérisation
-In condensation polymérisation, a molecule (usually water) is eliminated but in addition, no molecules are lost
-in condensation polymérisation, more than one product is formed, whereas in addition only one product is formed
Explain why fermentation is done in the absence of air(2)
1)so that anaerobic respiration can occur and ethanol can be made, OTEHRWISE, carbon dioxide and water would form instead for aerobic respiration
2)if air is present, oxygen will react with the ethanol to be oxidized and ethanoic acid will be formed and water
Give three properties of Carboxylic acids
React with metal carbonates to form carbon dioxide, salt and water
React with metals to form salt and hydrogen
React with alcohols with the presence of an acid catalyst to form esters
What type of an acid is a Carboxylic acid
A weak acid, so does not fully disassociate
Give a name of a condensation polymer
Nylon
