Question

Sum of basicity of ${H_3}P{O_4}$, ${H_3}P{O_3}$ and ${H_3}P{O_2}$ is equal to:
A. 3
B. 4
C. 5
D 6

Answer 1

Hint: Basicity of the chemical compound is the number of hydrogen atomsS present which can be replaced by other atomsS. In a chemical compound, for a hydrogen atomsS to be acidic it should be joined to the electronegative atomsS. Hence, basicity is defined as the number of acidic hydrogen atomsS.

Complete step by step answer:
In phosphoric acid ${H_3}P{O_4}$, three hydrogen atomsS, one phosphorus atomsS and four oxygen atomsS are present. In this compound, three hydrogen atomsS is joined with three oxygen atomsS. Therefore, the value of basicity is 3.
In orthophosphorous acid or phosphorous acid ${H_3}P{O_3}$ two types of bonding is present, where two P-OH bonds are present and one P-H bond is present. As two hydrogen atomsS are directly bonded with the electronegative atomsS oxygen. Therefore, the basicity of orthophosphorous acid or phosphorous acid is 2.
In hypophosphorous acid ${H_3}P{O_2}$ two types of bonds are present where two P-H bonds and one P-OH bond is present. As only one hydrogen atomsS is directly bonded to electronegative atomsS oxygen. Therefore, the basicity of hypophosphorous acid is 1.
Sum of the basicity = basicity of ${H_3}P{O_4}$+basicity of ${H_3}P{O_3}$ + basicity of ${H_3}P{O_2}$
$\Rightarrow$ Sum of the basicity = 3 + 2 +2
$\Rightarrow$ Sum of the basicity = 6.

Therefore, the correct option is D. .

Note: On the basis of replaceable hydrogen atomsS present in the acidic compound, the acidic compounds are determined as monobasic acid, dibasic acid and tribasic acid.