Question

the formula for hydro selenic acid is

Explanation:

Step1: Identify acid type

Hydro - prefix and -ic suffix in "hydro selenic acid" indicate it's a binary acid (composed of hydrogen and a non - metal). The non - metal here is selenium (Se).

Step2: Determine oxidation state and formula

In binary acids, hydrogen has an oxidation state of + 1. Selenium, like sulfur (in hydrosulfuric acid $\ce{H_2S}$), has a - 2 oxidation state in this acid. To balance the charges, we need 2 hydrogen atoms (each + 1) and 1 selenium atom (-2). So the formula is $\ce{H_2Se}$.

Answer:

$\ce{H_2Se}$