Question

Ammonia is a base but does not contain hydroxyl groups.

Answer 1

Hint: Ammonia is a weak base which on reacting with water does not dissociate into its constituent ion rather than it combines with water to form compound. It is a weak electrolyte.

Complete step by step answer:
A base is defined as the compound which on reaction with water liberates hydroxide ion $O{H^ - }$. The pH of the base is usually more than 7.
A strong base is the one which completely dissociates into its constituent ion when dissolved in water. The strong bases are used as strong electrolyte.
Example: Sodium hydroxide on reacting with water gives sodium ion and hydroxide ion.
$NaOH\xrightarrow{{{H_2}O}}N{a^ + } + O{H^ - }$
A weak base is the one which does not completely dissociate into its constituent ion. The weak base is considered as weak electrolyte.
Example: Ammonia on reacting with water forms ammonium hydroxide.
Ammonia is a base but it does not contain hydroxyl group because on reacting with water ammonia forms ammonium hydroxide which further on ionization gives ammonium ion and hydroxide ion.
The reaction of ammonia is shown below.
$N{H_3}\xrightarrow{{{H_2}O}}N{H_4}OH$
The ionization reaction of ammonium hydroxide is shown below.
$N{H_4}OH \to NH_4^ + + O{H^ - }$
As hydroxide ion is liberated on ionizing, even though ammonia does not have a hydroxyl group attached to it then also it is considered as base.

Note: The other definition for base is that it can donate its pair of electron with the neighbouring element. In ammonia, the central atom nitrogen is attached with three hydrogen atoms where nitrogen atom contains lone pair of electrons which it can donate to its neighbouring atoms.