Question | Answer |
What is the name of the reaction that produces alcohol from Ethene? | Hydration |
What is the type of reaction that produces alcohol from Ethene? | Electrophilic Addition |
What are the reaction condition where alcohol is produced from Ethene? | 300C, 60atm. Phosphoric Acid catalyst |
Describe what happens to the unreacted Ethene and Water during the hydration of Ethene that produces Ethanol | They are recycled and passed through the reactor again until 95% conversion is achieved |
Ethanol can be made by fermentation of sugar. What are the reaction conditions? | Yeast, anaerobic conditions, temperatures between 25 and 37C |
Ethanol can be made by fermentation of sugar. Why can we not get solutions of alcohol with a concentration higher than 14%? | The enzyme stops working/the yeast dies |
What would happen if Oxygen got in during fermentation of sugar? | Ethanol would be oxidised into Ethanal or Ethanoic Acid |
What is the equation for fermentation of sugar? | C6H12O6 --> 2 CH3-CH2-OH + 2 CO2 |
What is the equation for the Hydration of Ethene? | CH2=CH2 + H2O --> CH3-CH2-OH |
What is the disadvantage of the fermentation process compared to hydration? | Solution contains low concentration of alcohol and need to be further distilled; batch process |
What is the disadvantage of the hydration of Ethene compared to the fermentation process? | Uses non-renewable resources that could be used in other processes; high energy demand;high initial costs and maintenance costs for high-pressure vessel |
What is the equation for the Combustion of Ethanol? | CH3-CH2-OH + 3 O2 --> 2 CO2 + 3 H2O |
What is the equation for the Combustion of Methanol? | CH3-OH + 1.5 O2 --> CO2 + 2 H2O |
What is the advantage of the fermentation process compared to Hydration of Ethene | Renewable raw material; low energy demand |
Explain why countries like Brazil make Ethanol by fermentation rather than hydration? | Sugar cane is available; no reserves of crude oil |
Explain why Alcohol have a much higher bp than Alkanes with same number of Carbons | Strong Hydrogen bonds between Alcohol molecules; Weak VdW forces between Alkane molecules |
What must you include when drawing a Hydrogen bond | Ensure that you show the polarity of BOTH atoms on each bond (4 atoms in total!); show the lone pair on the oxygen; draw the "dashed" line between the O:|||H(delta+); finally ensure straight line |
What does "highly volatile" mean? | When a liquid turns into a gas really easily; ie does not need much energy to break bonds between molecule |
If a chemical has a high boiling point, is it volatile or not? | High boiling point = low volatility |
Explain why Alcohols are soluble in water | Because a Alcohol molecule can form a H-bond with water molecule |
Explain why Alcohols are less soluble as the length of the chain increases | Because the long Hydrocarbon chain can not form H-bond with water; the chain can not disrupt the H-bonds that exist between water molecules |
What is a primary alcohol? | When the Carbon that carries the OH group has been SUBSTITUTED only ONCE/has still got TWO Hydrogen atoms//is linked to THREE other carbon atoms |
What is a secondary alcohol? | When the Carbon that carries the OH group has been SUBSTITUTED TWICE/has still got ONE Hydrogen/is linked to TWO other carbon atoms |
What is a tertiary alcohol? | When the Carbon that carries the OH group has been SUBSTITUTED THREE times/has got NO Hydrogen left/is linked to THREE other carbon atom |
Classify Propan2ol as primary, secondary or tertiary alcohol | Secondary (two alkyl groups; one Hydrogen on the Carbon that carries the OH group) |
Classify CH3-CH2-CH2-OH as primary, secondary or tertiary alcohol | Primary (one alkyl groups; two Hydrogen on the Carbon that carries the OH group) |
Classify (CH3)3COH as primary, secondary or tertiary alcohol | Tertiary(three alkyl(methyl) groups; NO Hydrogen on the Carbon that carries the OH group) |
How many structural isomers for C4H10O? Name all of them. | 4: Butan-1ol; Butan-2ol; 2Methyl Propan-1ol; 2Methyl Propan-2ol |
What type of reaction takes place when an Alcohol is reacted with acidified Potassium DiChromate? | Oxidation |
What product is collected when a Primary Alcohol is reacted with acidified Potassium DiChromate under reflux? | Carboxylic Acid |
What product is collected when a Primary Alcohol is reacted with acidified Potassium DiChromate under distillation? | Aldehyde |
What are the reaction conditions if you want to collect a Carboxylic Acid from the oxidation of a Primary Alcohol with acidified Potassium Dichromate? | Heat under reflux |
What are the reaction conditions if you want to collect an Aldehyde from the oxidation of a Primary Alcohol with acidified Potassium Dichromate? | Distillation |
What product is collected when a Secondary Alcohol is reacted with acidified Potassium DiChromate under reflux? | Ketone |
What product is collected when a tertiary Alcohol is reacted with acidified Potassium DiChromate under reflux? | Nothing: the tertiary Alcohol can not get oxidised! |
Explain why Aldehydes have a lower boiling point than Alcohols | Alcohols have H-bonds between molecules whereas Aldehydes have permanent dipoles-permanent dipole interactions between molecules |
If Potassium Dichromate turns green under reflux during an oxidation reaction, can you deduce the class of alcohol? | No; the Alcohol could be Primary or Secondary |
What is the acid used to acidify Potassium Dichromate? | Dilute Sulfuric Acid |
What is the colour change when a Primary Alcohol is oxidised with acidified Potassium Dichromate? | From orange to green |
What is reflux? | Continuous boiling and condensing of a reaction mixture to ensure that no solvent is lost |
What product is formed when 2MethylHexan-1ol is oxidised under reflux? | 2MethylHexanoic Acid (you must first identify the TYPE of alcohol , then recall the pattern; then DRAW the structures of reactants, of products; then name) |
What product is formed when 2MethylHexan-1ol is oxidised under distillation? | 2MethylHexanal (you must first identify the TYPE of alcohol , then recall the pattern; then DRAW the structures of reactants, of products; then name) |
What product is formed when 3MethylHexan-2ol is oxidised under reflux? | 3MethylHexanone (you must first identify the TYPE of alcohol , then recall the pattern; then DRAW the structures of reactants, of products; then name) |
What are the products collected when an alcohol reacts with a carboxylic acid in the presence of an acid catalyst? | An ester and water |
What alcohol and Carboxylic acid are needed to produce Methyl Ethanoate | Methanol and Ethanoic Acid |
What are the conditions for the esterification reaction? | Concentrated Sulfuric Acid (as a catalyst), heat |
When forming an ester, how will the name of the alcohol change? | the Alcohol will provide the AlkYL part of the ester |
When forming an ester, how will the name of the carboxylic acid change? | The Carboxylic acid will provide the AlkanOATE part of the ester |
What are esters used for? | Adhesives, solvents and flagrances |
What is an esterification? | The reaction between an alcohol and a carboxylic acid to produce and ester and water |
What is a dehydration reaction? | It is an example of an elimination reaction in which water is removed; in an elimination reaction ONE reactant produces TWO products |
What are the conditions for the dehydration of an alcohol? | Concentrated Sulfuric Acid (or conc Phosphoric Acid), heat under reflux |
Describe which part of the alcohol molecule are lost during a dehydration reaction | The OH group on a given Carbon and the Hydrogen on the NEXT carbon along |
What are the names of the three isomers produced during the dehydration of Butan-2ol? | But-1-ene; E-But-2-ene; Z-But-2-ene (draw DISPLAYED form. of alcohol; work out 1st product by removing OH and H from adjacent C; draw alkene; check for E/Z; then work out 2nd product: remove OH + H from OTHER adjacent C; draw alkene; check for E/Z) |
What is the name of the product formed from the reaction of Butan-1ol and Ethanoic acid? | Butyl-Ethanoate |
What product is formed when 2MethylHexan-2ol is oxidised under reflux? | None because it is a tertiary alcohol! |
What product is formed when 2MethylCycloHexanol is oxidised under reflux? | 2MethylCycloHexanone (you must first identify the TYPE of alcohol , then recall the pattern; then DRAW the structures of reactants, of products; then name) |
Describe mechanism of elimination/dehydration of alcohols | Attack lone pair on O to H+; redraw as you see; check charges; simultaneous fold of C-O bond on the O and C-H to "between the two C" |
A compound is tested with Tollens reagent and a silver mirror forms. What do you infer? | The compound is an aldehyde |
A compound is tested with Fehling's reagent and a silver mirror forms. What do you infer? | The compound is an aldehyde |
What observation would you make for the reaction of an aldehyde and Tollens reagent? | A silver mirror forms |