Phosphoric acid, H3PO4(aq), is a triprotic acid. It helps in removing rust from iron, acidifying foods and beverages. It causes lowering of bone density.
Which of the following expressions correctly represents each of the ionizations that take place in the aqueous solution of phosphoric acid?
H3PO4(aq) → H+(aq) + H2PO4-(aq)
H2PO4-(aq) → H+(aq) + HPO42-(aq)
HPO42-(aq) → H+(aq) + PO43-(aq)
are you sure?
Apologies for the incorrect response.
The correct expressions for the ionizations of phosphoric acid in aqueous solution are as follows:
H3PO4(aq) → H+(aq) + H2PO4-(aq)
H2PO4-(aq) → H+(aq) + HPO42-(aq)
HPO42-(aq) → H+(aq) + PO43-(aq)
To determine the correct expressions for the ionizations of phosphoric acid, we need to consider that phosphoric acid is a triprotic acid, which means it can release three hydrogen ions (H+) successively in water.
The ionization reactions can be represented as follows:
1. First ionization:
H₃PO₄(aq) → H⁺(aq) + H₂PO₄⁻(aq)
2. Second ionization:
H₂PO₄⁻(aq) → H⁺(aq) + HPO₄²⁻(aq)
3. Third ionization:
HPO₄²⁻(aq) → H⁺(aq) + PO₄³⁻(aq)
These expressions represent the stepwise ionizations of phosphoric acid in an aqueous solution. Each ionization releases one hydrogen ion, resulting in the formation of the corresponding conjugate base. It is important to note that the concentration of each subsequent ionization becomes lower due to the decreasing acidity of the remaining species.
Overall, the correct expressions for the ionizations of phosphoric acid are:
1. H₃PO₄(aq) → H⁺(aq) + H₂PO₄⁻(aq)
2. H₂PO₄⁻(aq) → H⁺(aq) + HPO₄²⁻(aq)
3. HPO₄²⁻(aq) → H⁺(aq) + PO₄³⁻(aq)