4 Organics 2 COPY Flashcards
Use the method below to name the ester made from ethanol and methanoic acid
ethyl methanoate
Esters are very volatile (evaporate easily) and smell or taste sweet. What are esters used for?
fragrances in perfumes OR flavourings in food
Name the homologous series
carboxylic acid
How do you know that the formation of ethanoic acid from ethanol is oxidation?
ethanol has gained oxygen
What type of reaction is shown below?
Complete combustion of ethanol
It is an exothermic reaction
What are products for the reaction between ethanoic acid and sodium carbonate
metal carbonate + acid –> salt + water + carbon dioxide
Name the ester
ethyl hexanoate
Name the ester
ethyl butanoate
What conditions are needed to oxidise ethanol
potassium dichromate VI - oxidising agent
conc. sulfuric acid - catalyst
heat
NOT|E: mixture will turn from yellow to green
Describe how to safely make and smell an ester from ethanoic acid and propanol
- Place six drops of concentrated sulfuric acid into a test tube
- Add 1 cm3 of ethanoic acid
- Add 1 cm3 of propanol
- Swirl gently and add the test tube to a hot water bath
- Leave for 5 minutes
- Pour the mixture into a beaker of sodium carbonate to neutralise the concentrated acid
- Carefully waft the fumes towards your nose to identify the sweet ester smell
Name the ester
ethyl propanoate
Name the functional groups which are identified on this molecule
red = carboxylic acid (COOH)
green = ester (RCOOR’)
Name the two homologous series
alkane
AND
alcohol
What is the function of potassium dichromate (VI) in the oxidation of alcohols
potassium dichromate (VI) is the oxidising agent
It supplies oxygen [O]
It, itself is reduced
Name the products made from:
sodium carbonate and ethanoic acid
AND potassium metal added to propanoic acid
sodium hydroxide + ethanoic acid –> sodium ethanoate + water + carbon dioxide
potassium + propanoic acid –> potassium propanoate + hydrogen
Identify the homologous series
ester
Why is ethanoic acid a weak acid?
ethanoic acid does not fully dissociate into H+ ions
Only 4 in 100 molecules dissociate - less H+ ions = weaker acid
Name the homologous series depicted below
Carboxylic acid
What type of reaction is esterfication?
Condensation reaction
(water condenses out) leaving a carbon-oxygen bond between the carboxylic acid and alcohol
Use the method below to name the ester made from propan-1-ol and butanoic acid
propyl butanoate
Use the method below to name the ester made from
butan-1-ol and propanoic acid
butyl propanoate
What are the observations and products formed when magnesium is added to ethanoic acid
slight fizzing (as ethanoic acid is a weak acid)
magnesium ethanoate + hydrogen
Test for hydrogen- flaming splint goes squeaky pop
Name the identified functional groups on this molecule
OH = alcohol
COOH = carboxylic acid
What would happen if fermentation of glucose was carried out in the presence of oxygen or aerobically?
ethanol would oxidise to ethanoic acid
