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.
In this reaction, H2Se acts as the acid, and H2O acts as the base. The conjugate acid is H3O+ (hydronium ion), and the conjugate base is SeH- (selenide ion). Hydrogen selenide (H2Se) acts as the acid because it donates a proton (H+) to water, which acts as the base by accepting the proton. Hydrogen is more electronegative than selenium, causing the hydrogen-selenium bond to be polar, leading to the formation of the hydronium ion (H3O+) as the conjugate acid. The selenide ion (SeH-) is formed as the conjugate base.
In this reaction, H2Se is the acid and H2O is the base. The conjugate acid is H3O+ and the conjugate base is SeH-.
H2Se acts as the acid because it donates a hydrogen ion (H+) to water, forming the hydronium ion (H3O+). H2Se is classified as an acid because it contains a central selenium atom bonded to two hydrogen atoms, and selenium tends to exhibit acidic properties as it is located below sulfur in the periodic table.
On the other hand, water acts as the base because it accepts the hydrogen ion donated by H2Se, forming the hydroxide ion (OH-). Water has the ability to act as a base due to its lone pairs of electrons on the oxygen atom, which allow it to accept a proton and form a hydroxide ion. Overall, the acidity of H2Se and basicity of water in this reaction can be attributed to their positions in the periodic table and their chemical properties.
In the given reaction, H2Se is the acid, as it donates a proton (H+) to water. This makes water the base, as it accepts the proton. After the reaction, SeH– is the conjugate base of H2Se, as it is formed from the acid by losing a proton. Similarly, H3O+ is the conjugate acid of water, as it is formed by accepting a proton from the base.
The pattern on the periodic table helps us identify the acid and base in this reaction. Hydrogen selenide (H2Se), being a binary compound of hydrogen and selenium, follows the trend in acidity of binary hydrides across Period 2 of the periodic table. As we move from left to right across Period 2, the acidity of binary hydrides increases. Therefore, H2Se is acidic due to the higher electronegativity of selenium compared to hydrogen. Water (H2O), on the other hand, acts as a base in this reaction due to its ability to accept protons.