Equilibrium - LeChatelier's Principle and the Keq

Question

I am given this equilibrium equation : Co(H₂O)₆⁺² + 4Cl ^- <==> CoCl₄^-2 + 6H₂O

I need to find the concentrations of each of the compounds in order to calculate for the value of Keq. I know the concentrations of Co(H₂O)₆⁺², and Cl ^-, and CoCl₄^-2 because it is clear.

But how do you find the concentration of H₂O?

In 100.00 mL of 1M of CoCl2

I am given the following molarities:

[H+] = 9.84368e-8

[OH-] = 9.84368e-8

[Co(H₂O)₆⁺²] = 0.966539

[Cl ^-] = 1.86616

[CoCl₄^-2] = 0.0334612

Answer 1

The [H₂O] wouldn't be included in the equilibrium expression as it exists as a liquid, and liquids and solids are not included because their concentrations are deemed not to change.

Keq = [CoCl₄^2-] / [Co(H₂O)₆²⁺][Cl^-]⁴