Question

Use the periodic table to complete the activity.

An illustration shows the periodic table of elements with elements arranged in increasing order of atomic number in 18 columns (groups) and 7 rows (periods). The electronegativity of elements increases from left to right, across a period. The hydrogen on the left is included in group with medium electronegativity. Also, fluorine is shown as element with highest electronegativity.

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 1

[AI-generated answer — Bot GPT 3.5]

In this reaction, H2Se is the acid and H2O is the base. The conjugate acid is SeH- and the conjugate base is H3O+. Hydrogen selenide (H2Se) acts as the acid because it donates a proton (H+) to water (H2O), which acts as the base, accepting the proton. The pattern in the periodic table is that as you move from left to right across a period, electronegativity increases, making it more likely for an element to act as an acid and donate a proton.