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Acetic acid : properties

Acetic acid

source: wikipedia

source: Physics learn

Acetic acid-Chemical properties :

1) Acidic nature :

a) It neutralizes bases:

CH3COOH + NaOH ——-> CH3COONa  + H2O

b) It reacts with carbonates and bicarbonates evolving CO2.

2CH3COOH +Na2CO3 ——-> 2CH3COONa + H2O + CO2

CH3COOH + NaHCO3 —–> CH3COONa +H2O +CO2

c) Highly electropositive metals evolve H2 when react with CH3COOH.

2CH3COOH + 2Na ——–> 2CH3COONa + H2

d) It combines with alcohols in presence of dehydrating agent forming ester.

CH3COOH +C2H5OH ——> CH3COOC2H5 (ester) + H2O

e) It reacts with PCl5 or SOCl2 to give acetyl chloride

CH3COOH + PCl5 ——–> CH3COCl + POCl3 + HCl

CH3COOH + SOCl2 —–> CH3COCl + SO2 + HCl

2) Reaction with Cl2:

Acetic acid react with Cl2 in presence of Red Phosphorous  forming mono, di and tri-chloro acetic acid.

3) Dehydration :

Acetic anhydride is obtained when  heated in presence of  phosphorous pentaoxide (P2O5).

4) Borodine Hunsdiecker reaction :

Silver salt of carboxylic  acid is treated with Br2 or Cl2 in presence of carbon tetrachloride (CCl4). This method is used for the preparation of alkyl halides.

CH3COOAg + Br2    ———-> CH3Br + CO2 + AgBr

C2H5COOAg + Br2    ———-> C2H5Br + CO2 + AgBr

5) Schmidt Reaction :

 Primary amines are prepared by this method when acetic acid reacts  with hydrazoic acid in presence of concentrated H2SO4 at 00C then methyl amine is obtained.

CH3COOH + N3H ——-> CH3NH2 + CO2 + N2

6) Reduction :

a) When heated with HI/Red Phosphorous  or H2/Ni, ethane is obtained.

CH3COOH + 3H2 ——> CH3CH3 (ethane) +2H2O

b) When acetic acid (CH3COOH) is reduced by Lithium Aluminium Hydride ( LiAlH4) then ethyl alcohol is obtained.

CH3COOH + 4[H] ——> CH3CH2OH + H2O

7) Action of heat on salts :

a) When  Sodium acetate is heated with Soda-lime (a mixture of NaOH & CaO), methane is obtained.

CH3COONa +NaOH ——-> CH4 + Na2CO3

b) Acetamide is obtained when ammonium  acetate is heated.

CH3COONH4 ——-> CH3CONH2 +H2O

c) Methyl cyanide is obtained when ammonium acetate is heated with Phosphorous pentaoxide           (P2O5).

CH3COONH4 —–> CH3CN + 2H2O

d) Calcium  acetate on dry distillation gives acetone.

e) When Calcium acetate and Calcium formate are dry distilled then acetaldehyde ( CH3CHO) is            formed.

Saroj Bhatia: Dr. Saroj Bhatia is an Ph.D in chemistry who has been teaching chemistry for over a decade. Currently she is a respected principal of a renowned college in her hometown. She took this medium for online users. Her proudest achievement is helping people learn chemistry.
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