Hydrogen selenide (H2Se) reacts with water according to the following equation. H2Se H2O → SeH– H3O In three to five sentences, identify the acid, base, conjugate acid, and conjugate base in this reaction. Use patterns in the periodic table to explain why the substances you identified acted as the acid and the base in this reaction.

Answer and explanation:
The H2Se is the acid and HSe- is the conjugate base, whereas the H2O is the base and H3O+ is the conjugate acid.
The following points can be considered:
The substance which can donate a hydrogen ion is an acid;
The substance left after an acid donates hydrogen ion is its conjugate base;
The substance which can accept a hydrogen ion is a base;
The substance left after a base accepts a hydrogen ion is its conjugate acid.
Therefore, the answer is H2Se is the acid and HSe- is the conjugate base, whereas the H2O is the base and H3O+ is the conjugate acid.
1. In the periodic table, oxygen and selenium comes in the same group.
2. The electronegativity of the oxygen and the selenium highly differ.
3. The selenium accepts the electrons from the hydrogen and releases hydrogen ion.
4. The oxygen accepts the hydrogen ion with lone pair electrons present in it.