Alcohols and some of their Reactions Flashcards Preview

Chemistry 6 - Organic Chemistry > Alcohols and some of their Reactions > Flashcards

Flashcards in Alcohols and some of their Reactions Deck (31)

what are alcohols

- a homologous series of compounds
- with the general formula CnH2n+1OH


what are alcohols usually the product of

halogenalkanes going through hydrolysis


what symbol is used to represent an alkyl group



using that symbol, what is the simplified formula of an alcohol



what is a primary, secondary and tertiary alcohol

-a primary alcohol has the OH group bonded to only one carbon atom or alkyl group
- a secondary has it bonded to two
- and a tertiary has it bonded to three


what would be the abbreviated formula for primary, secondary and tertiary alcohols

- for primary it is ROH
- for secondary it is R2CHOH
- for tertiary it is R3COH


what are the three reactions of alcohols covered in this section

- combustion
- conversions to halogenalkanes
- dehydration of alkenes


what is the equation for the complete combustion of ethanol

C2H5OH + 3O2 = 2CO2 + 3H2O


what do the conversions of halogenalkanes invlove

replacing the hydroxyl group in an alcohol molecule with a halogen atom


what is the other name of this reaction that could be used, but what is the catch

- halogenation
- but adding a halogen to an alcohol doesnt work
- so different methods are needed for each halogen


what is the chlorination of an alcohol carried out using

- phosphorus V chloride
- a white solid also known as phosphorus pentachloride


why does the reaction between an alcohol and phosphorus V chloride not need heating

because the reaction is very vigorous and exothermic itself


what are the two inorganic products in this reaction

hydrochloric acid and phosphorus oxychloride


what is the structural formula equation for the reaction between propan-1-ol and phosphorus pentachloride

CH3-CH2-CH2OH + PCl5 = CH3CH2CH2Cl + POCl3 + HCl


how is the chlorination of tertiary alcohols done

the alcohol is mixed with concentrated hydrochloric acid, by shaking, at room temp


what is used to carry out bromination

- a mixture of potassium bromide
- and 50% concentrated sulfuric acid


what is done to carry out bromination

the reaction mixture is simply warmed with with the alcohol


what are the two inorganic products that could be produced and the product you want from either reaction

- you can get either potassium hydrogensulfate or potassium sulfate
- however the product you want from both reactions is hydrogen bromide


what is the hydrogen bromide then used to do

react with the alcohol


what would be the equation of the reaction between hydrogen bromide and butan-1-ol

CH3-CH2-CH2-CH2OH + HBr = CH3-CH2-CH2-CH2Br + H2O


what is used to carry iodination out and how is it done

- a mixture of red phosphorus and iodine is used
- the reaction mixture including the alcohol is heated under a reflux


what do the two inorganic reagents from when they react and what is the equation for this

- phosphorus (III) iodide
- 2P + 3I2 = 2PI3


what would the equation for the reaction between phosphorus iodide and ethanol

3C2H5OH + PI3 = 3C2H5I + H3PO3


what is the name of the inorganic product produced in this reaction

phosphonic / phosphorous acid


how is the dehydration of alcohols carried out

by heating the alcohol with concentrated phosphoric acid


what happens during this reaction

- the OH group and a hydrogen atom from an adjacent carbon atom is removed
- causing a C=C bond to form between the carbon atoms


why is this reaction called dehydration

because water is the inorganic product


what are the equations for the dehydration of butan-2-ol, without having to include the phosphoric acid

- CH3-CH(OH)-CH2-CH3 = CH2=CH-CH2-CH3 + H2O
- CH3-CH(OH)-CH2-CH3 = CH3-CH=CH-CH3 + H2O


what is the difference between the two organic products

- the first one is but-1-ene
- the second one is but-2-ene


why are there actually three different types of organic products that could form from this reaction

- because but-2-ene has two different isomeric forms using the E-Z notation
- including the but-1-ene which only has itself, it makes three


what happens to the phosphoric acid in the reaction

the water mixes with it and dilutes it