Question

A fuel cell differs from a battery because the current is being generated from a reduction-oxidation (redox) reaction in which the reactant is consumed. A classic example of a fuel cell is the phosphoric acid fuel cell (PAFC), which have been used in stationary power generators, buses, and even submarines. Fuel cells require an electrolyte (similar to batteries) to carry electrically charged species between the electrodes, and a PAFC utilizes phosphoric acid (H_3 PO_4) as its electrolyte. Phosphoric acid has three acidic protons that can dissociate in water as highlighted in red here: H_3 PO_4. However it is considered a weak acid because some of the acid will remain in molecular form when dissolved in water. Write the complete ionic equation that depicts the dissociation of the first proton for the weak acid phosphoric acid (H_3 PO_4). Make certain you include all charges for any ions produced. Express you answer as a chemical equation including phases. Given that a reaction can be presented in several different forms, we should make a clear distinction between each type of equation. The sulfate ion, SO_3^2- (aq), is very soluble with respect to most cations, and its fully protonated form, H_2 SO_3 (aq) (sulfurous acid), is a weak acid. Its singly protonated form, HSO_3^-, is also a weak acid. The following equations depict several reactions that could occur if sulfurous acid and sodium hydroxide were added to water. Classify each depicted reaction as being a molecular equation, a complete ionic equation, or a net ionic equation. Drag the equations to their respective bins.

Answer 1

The dissociation of
`H_(3)PO_(4)` is as follows.

`H_(3)PO_(4) \leftrightarrow H^(+)(aq)+H_(2)PO_(4)^(-)`

Step-by-step explanation:

Molecular equation:

In a molecular equation, reactants are present in the molecular form rather than ionic form.

`NaHSO_(3)(aq)+H_(2)O(l)\leftrightarrow H_(2)SO_(3)(aq)+NaOH(aq)`

Complete ionic equation:

An ionic equation shows the complete ions in the solution.

`Na^(+)(aq)+OH^(-)(aq)+H_(2)SO_(3)(aq)\rightleftharpoons Na^(+)(aq)+HSO_(3)^(-)(aq)+H_(2)O(l)`

Net ionic equation:

A reaction shows only those ions are participating in the reaction.

`HSO_(3)^(-)(aq)+OH^(-)(aq)\rightleftharpoons SO_(3)^(2-)(aq)+H_(2)O(l)`

The dissociation of
`H_(3)PO_(4)` is as follows.

`H_(3)PO_(4) \leftrightarrow H^(+)(aq)+H_(2)PO_(4)^(-)`.