Question

For a diprotic acid:
A. $p{K_{a1}} < p{K_{a2}}$
B. $p{K_{a1}} > p{K_{a2}}$
C. $p{K_{a1}} = p{K_{a2}}$
D. Can’t say.

Answer 1

Hint: We know that if an acid can donate two hydrogen ions or protons per molecule in an aqueous solution then it is called diprotic acid. Diprotic acid is also called dibasic acid.
We have to remember that the acidic proton is a diprotic and polyprotic acid which dissociates as a distinct and sequential step.

Complete step by step answer:
We know that a proton is a positively charged hydrogen atom, whereas an acid is a compound that releases a proton. Acids that are capable of liberating more than a single proton are recognized as polyprotic acids.
For polyprotic acids, \[{K_{a1}}\] is always the greatest followed by the second, etc.; this shows that the protons become consecutively less acidic as they are gone. Even though the affinity to lose each acidic proton decreases as following ones are lost, all possible ionic species do exist in solution; to determine their fractional concentration, one can know how to use equations to rely on equilibrium constants and the concentration of protons in solution.
So, the correct answer is “Option B”.

Additional Information:
The acidity of diprotic acids of chalcogen elements in an aqueous solution increases in the order${H_2}S < {H_2}Se < {H_2}Te$because the strength of an acid is depend on the stability of its conjugate base and as there is increase in the atomic size the strength of the bond between hydrogen and oxygen group atom decreases.

Note:
We have to remember that the polyprotic acids donate two or more acidic protons; diprotic acids and triprotic acids are some types of polyprotic acids that can donate two and three hydrogen ions respectively.
Polyprotic acids show as numerous equivalence points in titration curves depending on the number of acidic protons they have. For example, a diprotic acid will have two equivalence points, whereas a triprotic acid will have three equivalence points.