Question

How do I determine anhydrides of acid and base ?

Answer 1

Hint: Anhydrides are functional groups which are mainly the derivatives of either acids or bases. Acid anhydrides will have \[R - COO - CO - R'\] form where R and R' are alkyl groups. Although basic anhydrides will not have such an arrangement of atomic or molecular contacts.

Complete step by step answer:
Anhydrides are functional groups which are mainly the derivatives of either acids or bases
Fine, the acid anhydride is basically two equiv of the parent acid less a water molecule and therefore acetic anhydride is the anhydride of \[2\]equiv of acetic acid:
\[2{H_3}CC\left( { = O} \right)\left( {OH} \right){\text{ }} \to {\text{ }}{H_3}CC\left( { = O} \right)\left( O \right)C\left( { = O} \right)\left( {C{H_3}} \right){\text{ }} + {\text{ }}{H_2}O\]
And the base anhydride is an adult term that is recycled in inorganic chemistry; i.e. it mentions to \[2\]equiv of the hydroxide less water:
 \[2NaOH{\text{ }} \to {\text{ }}N{a_2}O + {H_2}O\]
 Natrium oxide is the base anhydride of (metal oxide) sodium hydroxide.
Other examples –
Non metal oxide : Acid anhydride
 Acid anhydrides are compounds that opportunity into an acid while you increase water. They are non-metal oxides. The oxides reveal periodicity with reverence to acidity. As you move across the period, the oxides develop more acidic. Sodium and magnesium oxides are alkaline. Aluminium oxides are amphoteric (racing together as a base or acid). Silicon, phosphorus, sulfur, and chlorine oxides are acidic. Some non-metal oxides, such as \[\left( {{N_2}O} \right)\] and \[\left( {Co} \right)\] do not exhibit several acid/base characteristics. These are a little more difficult than basic anhydrides.
Some examples of reactions connecting nonmetal oxides are as follows:
1. Is the anhydride of :
\[C{O_2}\left( g \right){\text{ }} + {\text{ }}{H_2}O\left( l \right){\text{ }} \to \;{H_2}C{O_3}\left( {aq} \right)\]
2. Reacts with water to procedure the weak acid,
\[S{O_2}\left( g \right){\text{ }} + {\text{ }}{H_2}O\left( l \right){\text{ }} \to {\text{ }}{H_2}S{O_3}\left( {aq} \right)\]
3. Procedures the strong with water (so, sulfur trioxide is the anhydride of sulfuric acid):
\[S{O_3}\left( g \right){\text{ }} + {\text{ }}{H_2}O\left( l \right){\text{ }} \to {\text{ }}{H_2}S{O_4}\left( {aq} \right)\]
This reaction is important in the creation of the acid.
Metal Oxides: Basic Anhydrides
Oxides of additional elements like the alkali or alkaline earth metals incline to be basic. They are called basic anhydrides, Visible to water, they may form bases (basic ).
Sodium oxide is basic-when hydrated, it forms. Here's extra example:
\[CaO\left( s \right){\text{ }} + {\text{ }}{H_2}O\left( l \right){\text{ }} \to \;Ca{\left( {OH} \right)_2}\left( {aq} \right)\]
Uncertainty the metal is an alkali or alkaline earth, the reaction maybe happens quickly and produces a proportion of heat. If the metal is a transition metal, the reaction might not occur so simply or at all.

Note:
Acid anhydrides are nonmetal oxides that react with water to procedure acids.
Basic anhydrides are metal oxides that react with water to procedure bases.