Answer :
Missing question:
A. H3PO4 (aq)<--> H+ (aq) + H2PO4- (aq).
B. H2PO4- (aq)<--> H+ (aq) + H2PO4-^2- (aq).
C. H3PO4 (aq)<--> 2H+ (aq) + HPO4^2-(aq).
D. HPO4^2- (aq)<--> H+ (aq) + PO4^3- (aq).
Answer is: A. H3PO4 (aq)<--> H+ (aq) + H2PO4- (aq).
The first dissociation constant :Ka₁ = [H+]·[H₂PO₄⁻] / [H₃PO₄].
In first dissociation phosphoric acid lost one proton (hydrogen ion).
A. H3PO4 (aq)<--> H+ (aq) + H2PO4- (aq).
B. H2PO4- (aq)<--> H+ (aq) + H2PO4-^2- (aq).
C. H3PO4 (aq)<--> 2H+ (aq) + HPO4^2-(aq).
D. HPO4^2- (aq)<--> H+ (aq) + PO4^3- (aq).
Answer is: A. H3PO4 (aq)<--> H+ (aq) + H2PO4- (aq).
The first dissociation constant :Ka₁ = [H+]·[H₂PO₄⁻] / [H₃PO₄].
In first dissociation phosphoric acid lost one proton (hydrogen ion).
In this exercise we have to set up an acid ionization equation that will be equal to:
[tex]H3PO4 (aq)<--> H+ (aq) + H2PO4- (aq).[/tex]
How to write ionization equation?
The ionization of an acid is a chemical process that involves the production of ions when an acid is dissolved in water, with the formation of the hydronium cation (H+). The ionization of acids is a chemical phenomenon that occurs with these inorganic substances when they are mixed with water, which results in a homogeneous mixture.
In this way we can write as:
[tex]H3PO4 (aq)<--> H+ (aq) + H2PO4- (aq).[/tex]
See more about acid ionization at brainly.com/question/6071977