Question

You're provided with a bottle labled [CoCl2.6H2O] = 0.054 M in 4.60 M HCl. You heat a small volume of the solution in a hot water bath to 50 ∘C. If you determine that [CoCl42-] = 0.034 M at 50 ∘C at equilibrium, what must be the equilibrium concentration of [Cl-] at 50 ∘C?

Answer 1

Answer: The equilibrium concentration of chloride ions in the solution is 4.532 M

Step-by-step explanation:

We are given:

Initial molarity of
`[CoCl_2.6H_2O]` = 0.054 M

Initial molarity of HCl = 4.60 M

Equilibrium molarity of
`[CoCl_4]^(2-)` = 0.034 M

The chemical equation for the reaction of
`[CoCl_2.6H_2O]` and HCl follows:

`[CoCl_2.6H_2O]+2HCl\rightarrow H_2[CoCl_4]+6H_2O`

Or,

`[CoCl_2.6H_2O]+2Cl^-\rightarrow [CoCl_4]^(2-)+6H_2O`

Initial: 0.054 4.60

At eqllm: 0.054-x 4.60-2x x 6x

Evaluating the value of 'x':

`x=0.034`

So, equilibrium concentration of
`Cl^-` = (4.60 - 2x) = [4.60 - 2(0.034)] = 4.532 M

Hence, the equilibrium concentration of chloride ions in the solution is 4.532 M