Question | Answer |
Organic chemistry | |
What is the formula of ethanol? | CH3-CH2-O-H or C2H5OH |
Describe the conditions for the production of ethanol by fermentation of carbohydrates | warm temperatures (between 35 and 40C), under anaerobic conditions, with yeast to provide an enzyme for this reaction |
Write the equation for the fermentation of sugar | C6H12O6 (+ yeast) 2 CO2 + 2 C2H5OH |
Describe disadvantages of production of ethanol by fermentation | The reactant (sugar) requires a lot of land and suitable climate; the product of fermentation is a mixture that needs to be separated by fractional distillation; it is a batch process and takes a long time |
What is the equation for the production of ethanol by hydration of ethane? | C2H4 + H2O C2H5OH |
What is the equation for the DEhydration of ethanOL? | C2H5OH C2H4 + H2O |
Describe disadvantages of production of ethanol by hydration of Ethene | The reactant (ethene) is coming from a non-renewable source (crude oil); a lot of energy is required to maintain high temperature |
Describe advantages of production of ethanol by hydration of Ethene | It is a continuous process |
Describe advantages of production of ethanol by fermentation | The reactant (sugar) is coming from a renewable source (plants); little energy is required |
Define a homologous series | a series of compounds which: have the same general formula; differ by a CH2; show a gradual variation in physical properties as exemplified by their boiling points; have similar chemical properties |
Name the first 4 alcohols | Methanol, Ethanol, Propanol and Butanol |
Name the first 4 carboxylic acids | Methanoic acid, Ethanoic acid, Propanoic acid and Butanoic acid |
What is the general formula of AlkAnes? | CnH2n+2 |
What is the general formula of AlkEnes? | CnH2n |
Describe the reaction that happens to Ethanol left in a room? | Ethanol will oxidise (react with Oxygen) to become Ethanoic Acid |
Describe the use of vinegar | as a flavouring and as a preservative |
Name the products of reaction of ethanoic acid with a metal like Magnesium | Hydrogen gas and a salt, Magnesium Ethanoate |
Name the products of reaction of ethanoic acid with bases, like Sodium Hydroxide | Water and a salt, Magnesium Ethanoate |
Name the products of reaction of ethanoic acid with carbonates | Carbon Dioxide gas and a salt, Magnesium Ethanoate |
Describe what you would see when you place ethanoic acid in universal indicator | the indicator will turn red |
Describe what you would see when you react ethanoic acid with sodium carbonate | Bubbles of carbon dioxide gas |
Describe what you would see when you react ethanoic acid with Calcium | Bubbles of hydrogen gas |
Name the products of reaction of ethanol with ethanoic acid | ethyl ethanoate and water |
Name the products of reaction of propanol with ethanoic acid | propyl ethanoate and water |
Name the products of reaction of methanol with butanoic acid | methyl butanoate and water |
Write the equation for the reaction of ethanol with ethanoic acid using molecular and structural formulae | CH3-CH2-O-H + CH3-CH2-CO-O-H CH3-CH2-CO-O-CH2-CH3 + H2O |
What is the structural formula of Ethyl Ethanoate? | CH2-COO-CH2-CH3 |
Describe uses of esters | as flavourings and perfumes, as they are pleasant smelling |
Describe uses of polyesters | as fibres to make fabric and as plastics for making bottles |
can polyesters be recycled? | yes, to form fleece that is used to make clothing |
Describe the structure of oils and fats | they are tri-esters of glycerols |
Describe how oils can be converted to soap | By boiling with concentrated sodium hydroxide |
Name the products of the reaction of oils and fats when boiling with concentrated alkali solution | soaps and glycerol |
Describe the structure of soaps | sodium or potassium salts of long carbon chain carboxylic acids |
Describe how a soap removes dirt or grease | part of the soap, the head, is an anion is hydrophilic and dissolves in water; the other part, the tail, is hydrophobic and will dissolves in dirt or grease; a micelle forms and lifts away the grease spot; the micelle is washed away with rinsing waters |
Describe how liquid oils can be converted to solid fats | by catalytic hydrogenation |
Describe what happens to the oil structure during catalytic hydrogenation | the C=C unsaturation is removed when the Hydrogen adds on either side of the C=C bond |
Describe how oil can be converted to margarine | add H2 to the oil with a Nickel catalyst |
How would you draw an oil? | Draw a coat hanger; add C=O; add a wiggly chain |