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Description
Flashcards by Bee Brittain, updated more than 1 year ago
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Created by Bee Brittain
about 8 years ago
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| Question | Answer |
| What is volatility? | The tendency of a substance to vapourise |
| Why do Alcohols have low volatility? Does this mean they have a high, or low boiling point? | Alcohols have low volatility because when they're in liquid form, they have hydrogen bonds which are quite strong and require lots of energy to break. This also means alcohols have a high boiling point. |
| Are alcohols a polar molecule? | Yes. This is because of their OH bond and there is a difference in electronegativity between the oxygen and hydrogen, making it a polar molecule. |
| Alcohols have weak London forces, but what other type of force/bond do they have that determines their properties? | Hydrogen Bonds |
| Are Alcohols soluble in water? Reason your answer. | Yes. This is because they are a polar molecule, so they can form hydrogen bonds between themselves and water molecules, making them soluble. |
| If the carbon chain in the alcohol gets longer, what happens to its solubility? | I |
| Name the three classification of alcohols. | Primary Secondary Tertiary |
| What is a Primary alcohol? | A Primary alcohol is when the -OH group is attached to a Carbon atom, that has two H atoms, and one other alkyl group attached to it. |
| What is a Secondary Alcohol? | A secondary alcohol is when the -OH group is attached to a Carbon atom, that is attached to one H atom and two alkyl groups. |
| What is a Tertiary alcohol? | A tertiary alcohol is when the -OH group is attached to a Carbon atom that is also attached to no Hydrogen atoms, but 3 other Carbon atoms. |
| What is oxidation? | Oxidation is when something is oxidised (loses electrons, adds oxygen) while something is reduced (gains electrons). |
| If a primary alcohol is oxidised, what is initially produced, and what process is required to get this product? | The product initially produced, is an Aldehyde. Slightly acidic Potassium Dichromate is added to the alcohol and it is distilled out of the mixture as it is formed. |
| If the aldehyde isn't distilled from the mixture, something else is formed. What is this product and why is it formed? | The product formed is Carboxylic acid. It is formed because if the reaction has conditions to carry on, or is under reflux with heat and excess potassium dichromate, the alcohol gets oxidised to an aldehyde, and then the aldehyde gets further oxidised to a Carboxylic acid. |
| What is produced if a secondary alcohol is oxidised? | A ketone. |
| How is the product of the oxidation of secondary alcohols formed? And under what conditions? | The ketone is formed by heating the alcohol under reflux with potassium dichromate (which is an oxidising agent). |
| What happens is you oxidised a Tertiary alcohol? | Nothing as tertiary alcohols do not under go oxidation reactions. |
| If the alcohol is oxidised, what happens to the potassium dichromate? If the alcohol isn't oxidised, what happens to it? | If the alcohol is oxidised, it turns from orange to green. However if it isn't oxidised, the potassium dichromate stays the same. |
| If an alcohol is completely burned in a plentiful supply, what are the products? | Carbon Dioxide and water |
| Is the combustion of alcohols an endothermic or exothermic reaction? | Exothermic - a large amount of heat/energy is released. |
| If there are more carbon atoms in the alcohol chain, what happens to the amount of energy released in combustion? | As the number of carbons in the carbon chain increases, the amount of energy per mole also increases. |
| What happens in a Dehydration reaction? | In a dehydration reaction, a molecule of water is taken from the starting material. |
| How is a dehydration reaction of an alcohol carried out? | The alcohol is heated under reflux in the presence of an acid catalyst, such as H2SO4 or H3PO4. |
| Dehydration is an example of what type of reaction? | An elimination reaction. |
| What happens in a substitution reaction with an alcohol? | The alcohol is reacted with a halogen halides to form haloalkane |
| How is a substitution reaction prepared? | The alcohol is heated under reflux with H2SO4 |
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