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)