0.1 mol of HCl is added to 1 L of water.

What is [H+] and [OH-]?

See your post below.

To determine the concentration of [H+] and [OH-], we need to consider the dissociation of HCl in water.

HCl dissociates completely in water to form H+ and Cl-. Since the moles of HCl are given as 0.1 mol and the volume of water is 1 L, the concentration of HCl can be calculated as follows:

[HCl] = (moles of HCl) / (volume of water)
[HCl] = 0.1 mol / 1 L
[HCl] = 0.1 M

Based on the stoichiometry of the HCl dissociation, the concentration of H+ will be the same as the initial concentration of HCl:

[H+] = [HCl] = 0.1 M

Since water is a neutral substance, the concentration of OH- can be calculated from the formula:

[H+] x [OH-] = 1 x 10^-14

Substituting the value of [H+] as 0.1 M into the formula:

(0.1 M) x [OH-] = 1 x 10^-14

Solving for [OH-]:

[OH-] = (1 x 10^-14) / (0.1 M)
[OH-] = 1 x 10^-13 M

Therefore, the concentration of [H+] is 0.1 M, and the concentration of [OH-] is 1 x 10^-13 M in the water solution.