Exercise 8: ALCOHOLS Flashcards by Blueberry Cheesecake

which is the
active component of alcoholic
beverages, is just one and most common
among the large family alcohols.

Ethanol (ethyl alcohol)

How well did you know this?

Not at all

Perfectly

organic compounds composed of an aliphatic carbon atom with a
hydroxyl (-OH) functional group

 very common and may exist freely in nature

 exhibit some unique set of physicochemical properties mainly due to
the presence of the hydroxyl functional group

Alcohols

How well did you know this?

Not at all

Perfectly

 the is a functional group of all alcohols, hence the
general formula of ROH, where R is the alkyl group

hydroxyl group

How well did you know this?

Not at all

Perfectly

 some of the properties of alcohols depend on the

length of the alkyl chain attached to the hydroxyl group

How well did you know this?

Not at all

Perfectly

 C with the –OH group attached to one other carbon atom
 general formula:

primary (1°) alcohol

RCH2OH

How well did you know this?

Not at all

Perfectly

 C with the –OH group attached to two other carbon atoms
 general formula:

 secondary (2°) alcohol

R2CHOH

How well did you know this?

Not at all

Perfectly

 C with the –OH group attached to three other carbon
atoms
 general formula:

 tertiary (3°) alcohol

R3COH

How well did you know this?

Not at all

Perfectly

generally have higher boiling points as compared to hydrocarbons
having the same molecular masses

mainly due to the in between the OH
groups

BOILING POINT

intermolecular H-bonding

How well did you know this?

Not at all

Perfectly

boiling point = number of C in the aliphatic chain
boiling point  = branching in aliphatic carbon chain 

Increase. Increase
Decrease, increase

How well did you know this?

Not at all

Perfectly

governed by its ability to perform intermolecular H-bonding with
polar solvents

SOLUBILITY

How well did you know this?

Not at all

Perfectly

 are usually formed in between the OH group of alcohol
and water (which makes alcohol soluble with H2O)

however, the longer the alkyl chain is, the - alcohol
becomes soluble with water

H-bonds

lesser

How well did you know this?

Not at all

Perfectly

acidic in nature because of their ability to react with active metals
(e.g. sodium, potassium,) forming the corresponding

ACIDITY
alkoxide

How well did you know this?

Not at all

Perfectly

acidity is due to the

polarity of the hydroxyl bond

How well did you know this?

Not at all

Perfectly

acidity  = when an electron donating group is attached to the
hydroxyl group as the electron density increases on the oxygen
atom

Decrease

How well did you know this?

Not at all

Perfectly

primary alcohols are - than secondary and tertiary
alcohols

more acidic

How well did you know this?

Not at all

Perfectly

PROPERTIES OF ALCOHOLS

Boiling point
Solubility
Acidity

How well did you know this?

Not at all

Perfectly

alcohols exhibit a
range of
spontaneous
chemical
reactions due to

the cleavage of
C-O and O-H
bonds

How well did you know this?

Not at all

Perfectly

JONES TEST (CHROMIC ACID TEST) results

n-butyl alcohol

blue-green solution
changes color much faster

How well did you know this?

Not at all

Perfectly

JONES TEST (CHROMIC ACID TEST) results

sec-butyl alcohol

blue-green solution
changes color much slower

How well did you know this?

Not at all

Perfectly

JONES TEST (CHROMIC ACID TEST) results

tert-butyl alcohol

orange solution
n/a

How well did you know this?

Not at all

Perfectly

used to distinguish primary and
secondary alcohols from tertiary alcohols

 positive result: blue-green solution

JONES TEST (CHROMIC ACID TEST)

How well did you know this?

Not at all

Perfectly

 reagent: Jones reagent ();

chromium oxide CrO3 in sulfuric acid H2SO4

How well did you know this?

Not at all

Perfectly

JONES TEST (CHROMIC ACID TEST) named after

named after Ewart Jones

JONES TEST (CHROMIC ACID TEST) principle: detect polar functional groups that can
be oxidized:

are oxidized to carboxylic acid while
to ketones; the
is reduced to a - species, which often precipitates in acetone

1° alcohols and aldehydes

2° alcohols

orange hexavalent chromium (Cr6+), blue-green trivalent chromium (Cr3+)

LUCAS TEST results n-butyl alcohol

Clear colorless soln N/a

LUCAS TEST results n-butyl alcohol

clear colorless solution n/a

LUCAS TEST results sec-butyl alcohol

two-layer solution forms layer much slower

LUCAS TEST results tert-butyl alcohol

Turbid solution immediate

LUCAS TEST results benzyl alcohol

turbid solution often immediate

used to distinguish tertiary and secondary alcohols from primary alcohols  positive result: turbid solution/formation of two layers

LUCAS TEST

 reagent: Lucas reagent

zinc chloride ZnCl2 in concentrated hydrochloric acid HCl)

 positive result: lucas test

turbid solution/formation of two layers

LUcas test named after

Howard Lucas

positive result: Jones Test

blue-green solution

LUCAS TEST principle: SN1 mechanism to produce - which appears as white precipitate or cloudiness of the solution; often give immediate results like tertiary alcohols

insoluble alkyl chloride benzyl, allylic and propargylic alcohols

ESTERIFICATION REACTION results methanol + salicylic acid

minty odor immediate

function of test: used to demonstrate reactivity of alcohols with carboxylic acids when heated with acid catalyst  positive result: methanol with salicylic acid results to minty odor (methyl salicylate); esters results to characteristic fruity-like odor

ESTERIFICATION REACTION

 positive result: Esterification rxn

methanol with salicylic acid results to minty odor (methyl salicylate); esters results to characteristic fruity-like odor

reaction is both slow and reversible

Fischer esterification reaction;

TEST FOR METHANOL COLOR

red-violet ring at the junction of the two layers with dark red flocculent precipitate

function of test: demonstrate oxidation of alcohols through partial oxidation and dehydrogenation using hot catalyst (heated copper)

TEST FOR METHANOL

TEST FOR METHANOL  principle: methanol is oxidized to - using - as catalyst; to detect if methanol was oxidized, - is added to the solution and - is added dropwise to induce color change, precipitates and layer formation (method was introduced by)

methanal (formaldehyde), heated copper resorcinol, concentrated sulfuric acid) Robert Mulliken

IODOFORM TEST results ethanol

clear colorless solution

IODOFORM TEST results isopropyl alcohol

turbid yellow solution with canary yellow precipitate

IODOFORM TEST results methanol

clear colorless solution

function of test: used to identify methyl ketones or secondary alcohols adjacent to a methyl group  positive result: turbid yellow solution/canary yellow precipitate

IODOFORM TEST

 reagent: Wagner’s reagent ; is used to decolorize the solution

iodine in potassium iodide) sodium hydroxide

 positive result: Iodoform Test

turbid yellow solution/canary yellow precipitate

Iodorm Test principle: I2 in KI in NaOH reacts only for compounds with the structure to form (canary yellow precipitate); does not work for all alcohols or ketones and does not work also for water-insoluble compounds

RCH(OH)CH3 or RC=OCH3, iodoform

ACROLEIN TEST results glycerol

pungent acrid odor

used to detect the presence of glycerol  positive result: pungent acrid odor

ACROLEIN TEST

 sample: - a polyhydroxy alcohol (triol) obtained as a by- product from the manufacture of soap used as a moisturizing agent in cosmetic formulations

glycerol

AcroleinTest  principle: when heated with, glycerol is dehydrated to form

potassium bisulfate (KHSO4), propenal (acrolein)

eagent: Wagner’s reagent

Iodoform Test

reagent: Lucas reagent

Lucas Test

reagent: Jones reagent

Jones Test