NAME: EDET GIDEON CHRISTOPHER

MATRIC NUMBER: 19/MHS02/042

DEPARTMENT: NURSING

COURSE CODE:CHM102

Give the IUPAC names of the following compounds

HCOOH- Methanoic acid

HOOCCH2CH2CH2COOH- Pentan-1,5-dioic acid

CH3CH2CHCOOH- Butanoic acid

HO2C-CO2H- Ethanedioic acid

CH3(CH2)4COOH-Hexanoic acid

CH3CH=CHCH2CH2COOH- Hex-4-eneoic acid

Discuss briefly the physical properties of carboxylic acids under the following headings

Physical apperance: All simples aliphatic carboxylic acids up to C10 are liquids at room temperarure. Most other carboxylic acids are solid at room temperature although annhydrous carboxylic acid (acetic acid) also known as glacial ethanoic acid freezes to an ice like solid below the room temperature.

Boiling points: Boiling points increases with increasing relative molecular mass. Aromatic carboxylic acids are crystalline solids have higher melting points than their aliphatic counterparts of comparable relative molecular mass.

Solubility: Lower molecular mass carboxylic acids with up to four carbon atoms in their molecules are soluble in water; this largely due to their ability to from hydrogen bonds with water molecules. The water solubility of the acids decreases as the relative molecular mass increases because the structure becomes relatively more hydrocarbon in nature and hence covalent. All carboxylic acids are soluble in organic solvents.

Write two industrial preparations of carboxylic acids.

From carbon(ii) oxide: Methanoic acid is manufactured by adding carbon(ii)oxide under pressure to hot aqueous solution of sodium hydroxide. The free carboxylic acid is liberated by careful reaction with tetraoxosulphate(Vi) acid (H2SO4)

NaOH H2SO4

CO--------HCOONa------------ HCOOH+ NaHSO4

From Ethanol: Ethanoic acid is obtained commercially by the liquid phase air-oxidation of 5% solution of ethanal to ethanoic acid using manganite(ii) ethanoate catalyst. Ethanal itself is obtained from ethylene.

_ Dil.H2SO4/HgSO4 O2/(CH3COO)2Mn

HC= CH ----------------------------CH3CHO---------------------------CH3COOH

With equations and brief explanations discuss the synthetic preparation of carboxylic acid

Oxidation of primary alcohols and aldehydes: oxidation of primary alohols and aldehydes can be used to prepare carboxylic acids using the usual oxidizing agents (i.e k2cr2O7 or KmnO4) in acidic solution

[O] excess acid/KMnO4 [O]

RCH2OH------------------------------RCHO--------RCOOH

Carbonation of Gringard reagent: Aliphatic carboxylic acids are obtained by bubbling carbon(IV) oxide into the Gringnard reagent and then hydrolyzed with dilute acid.

(C2H3)2O H2O/Dil. acid

RMgBr + CO2---------------RCOOMgBr----------------------RCOOH+MgBrOH

Hydrolysis of nitriles( cyanides) or esters

H+

RCN+ 2H2O------RCOOH+NH4+

H2O/H+ reflux

RCOOR’------------------------RCOOH + R’OH

H+

C6H5CH2CN+ 2H2O------------------C6H5CH2COOH+NH4+

H2O/H+reflux

CH3CH2COOCH3-----------------------CH3CH2COOH+CH3OH

With chemical equation only, outline the reduction, decarboxylation and esterification of carboxylic acid.

4RCOOH+3LiAIH4------------------(RCH2O)4AILi+2LiAIO2+4H2

I

I 4H2O

I

4RCH2OH+AI(OH) +LiOH

LiAIH4

CH3CH2CH2COOH----------CH3CH2CH2CH2OH

Butanoic acid butanol

Decarboxylation

fuse

CH3CH2CH2COONa+NaOH--------- CH3CH2CH3+----Na2CO3

Kolbe synthesis

Electrolysis/aq. CH3OH

2CH3CH2COONa+2H2O--------------------------------CH3(CH2)2CH3+CO2(Anode) +2NaOH+H2(cathode)

Estherification

H+

CH3CH2CH2COOH+CH3CH2CH2OH-CH3CH2CH2COOCH2CH2CH3+H2O