Question

One of the acids listed below is formed only from ${P_2}{O_3}$; the rest are formed from ${P_2}{O_5}$. Acid from ${P_2}{O_3}$ is:
A.$HP{O_3}$
B.${H_4}{P_2}{O_7}$
B.${H_3}P{O_4}$
D.${H_3}P{O_3}$

Answer 1

Hint: Acids: Those species which can donate protons, are known as acids. For example: carboxylic acid.
Base: Those species which can accept protons, are known as base. For example: sodium hydroxide.

Complete step by step solution:
Let us first talk about acids, bases.
Acids: Those species which can donate protons, are known as acids. For example: carboxylic acid.
Base: Those species which can accept protons, are known as base. For example: sodium hydroxide.
The acids formed by diphosphorus trioxide i.e. ${P_2}{O_3}$ are as: ${H_3}P{O_3}$. When diphosphorus trioxide i.e. ${P_2}{O_3}$ reacts with water then ${H_3}P{O_3}$ i.e. phosphorus acid will form. The reaction is as: $2{P_2}{O_3} + 6{H_2}O \to 4{H_3}P{O_3}$.
And the rest acid i.e. $HP{O_3}$, ${H_4}{P_2}{O_7}$ ad ${H_3}P{O_4}$ are formed by ${P_2}{O_5}$ which is known as phosphorus pentoxide.
The reactions for these acids are as:
$2{P_2}{O_5} + 6{H_2}O \to 4{H_3}P{O_4}$. The acid formed during this reaction is known as phosphoric acid.
When phosphorus pentoxide reacts with phosphoric acid then metaphosphoric acid i.e. $HP{O_3}$ is formed. The reaction is as ${H_3}P{O_4} + {P_2}{O_5} \to 3HP{O_3}$.
And when phosphorus pentoxide reacts with water then diphosphoric acid i.e. ${H_4}{P_2}{O_7}$ is formed. The reaction is as: ${P_2}{O_5} + 2{H_2}O \to {H_4}{P_2}{O_7}$.
From the above reactions we can clearly see that only phosphoric acid is formed by diphosphorus trioxide and rest all the acids i.e. phosphoric acid, diphosphoric acid and metaphosphoric acid are formed by phosphorus pentoxide.

Hence option D is correct.

Additional information:
Oxoacids: They are the acids that contain oxygen, hydrogen and at least one other atom and there should be at least one hydrogen atom which is bonded to oxygen due to which the compound acts as acid (because the hydrogen will release). For example: phosphoric acid, metaphosphoric acid, diphosphoric acid, etc. They all are the examples of oxoacids of phosphorus.

Note:
Amphiprotic species: The species which can donate as well as can accept proton i.e. can act as acid as well as base, are known as amphiprotic species. For example: amino acids, water, hydrogen carbonate ions.