Carboxylic acid and NaOH reaction and mechanism

Carboxylic acid is a weak acid. It dissociates partially in the water to give acidic solution. Also NaOH is a strong alkali and give hyroxyl ions. So carboxylic acid reacts with aqueous NaOH to give the salt and water like other acid - base reactions.


Sodium carboxylate ion is given as the salt. Water is also produced. In following examples, we discuss some reactions of carboxylic acids and aqueous NaOH. This reaction is an exothermic reaction which releases heat to the outside when reaction is being haappened. Therefore temperature of the reaction mixture increases with time.

Is sodium carboxyate is acidic or basic or neutral?

Strong base and weak acid react and produce weak basic salt. So, sodium carboxylate has weak basic characteristics.

Ethanoic acid and aqueous NaOH

Sodium ethanoate and water are given by the reaction of ethanoic acid and aqueous NaOH. Sodium ethanoate is soluble in water.

Benzoic acid and NaOH reaction

Benzoic acid reacts with aqueous NaOH to sodium benzoate salt. Benzoic acid is a white precipitate. But during the reaction, that precipitate dissolve in aqueous phase. That tells us, sodium benzoate is soluble in water due to forming positive and negative ions.

carboxylic acid NaOH reaction

Acidity of carboxylic acid

From NaOH and carboxylic acid reaction, we can say carboxylic acids are more acidic than alcohols. Alcohols do not react with aqueous NaOH.


Hydrogen atom in the -OH of carboxylic acid positively charged and has the acidic property. OH- provided from NaOH is like to attack that acidic H+.

With that attack, acidic hydrogen and oxygen bond is broken and two electrons of the broken bond goes to the oxygen atom to give carboxylate anion (CH3COO-). Hydrogen atom is combined with OH- to form the H2O molecule.

Now, Na+ ion is combined with carboxylate ion (CH3COO-).

Benzoic acid and NaOH reaction mechanism

The hydrogen atom in the -OH group of benzoic acid is attacked by the OH- of NaOH to form the H2O molecule. Then -OH hroup of benzoic acid is broken and bond electrons are gone to the oxygen atom by producing -O- (benzoate ion). Then Na+ cation is combined with benzooate anion to form sodium benzoate.

Explanation of carboxylic acid + NaOH reaction with equilibrium point

Think like this. Aqueous arboxylic acid solution is on the flask. Aqueous NaOH solution is added to carboxylic acid solution drop by drop.

Added NaOH reacts with H+ ions which are given from carboxylic acid. So H+ ion concentration decreases which will affect to the equilibrium point of carboxylic acid.

To minimize the effect, equilibrium point shifts to the right by producing H+ ions and RCOO- ions furthermore.

What happen to equilibrium and equilibrium point of aqueous carboxylic acid after adding NaOH?

Due to form of carboxylate ion, equilibrium point shifts to the left side. Otherwise we can say, dissociation decreases.

Is carboxylic acid + NaOH reaction an oxidizing reducing reaction?

No, this is a just an acid - base reaction.

If Na metal add to the carboxylic acid, that also gives sodium ethanoate with hydrogen gas. That is an redox reaction (oxidizing reducing reaction).

Benzoic acid hydrogen bond in naoh?

This question is not cleaar and but I can give an explanation to it. Benzoic acid can form hydrogen bond with water. Also aqueous NaOH can form hydrogen bonds with water.


What are the uses of these reactions?

This reaction can be used to identify alcohols from carboxylic acids because alcohols do not react with aqueous NaOH. But, we cannot identify phenol from carboxylic acid because phenol reacts with aqueous NaOH.

where will the sodium go in a with a carboxylic acid?

Sodium metal and sodium hydroxide both react with carboxylic acid. However after the reaction, sodium is oxidized and should exist as Na+ ion. Carboxylic acid is transferred to carboxylate ion and sodium ion is gone to -O- (-COO-).

What happens when benzoic acid reacts with Ba(OH)2?

Barium hydroxide ( Ba(OH)2 ) is a strong base in a aqueous solution and reacts with benzoic acid. and produce barium benzoate.

carboxylic acid reacts with a strong base to give what products?

Carboxylic acid reacts with strong bases such NaOH, KOH to produce weak basic salts.

Organic Chemistry Problems and Answers