Question

What is the basicity of ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$?

Answer 1

Basicity

• The basicity is a measure of the ability to accept a proton $\left({\mathrm{H}}^{+}\right)$ to form a stable product

Basicity of acid

• The Basicity of an acid is defined as the number of replaceable hydrogen atoms of that particular acid by a base.

Basicity of ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$

• Only those $\mathrm{H}$atoms which are attached with oxygen in $\mathrm{P}–\mathrm{OH}$ form are ionizable and cause the basicity.
• The structure of ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$ is as follows:-

• In the above structure, four $\mathrm{H}$atoms are attached with oxygen.
• So, ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$ is tetrabasic acid and basicity of ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$ is $4$.