# Equilibrium Lab

#### General_Sax

1. Homework Statement

COCL4 + 6H2 <=> Co(H20) +4CL

blue <=> pink

Question: Add a very small amount of AgNO3 to test tube #6. Stopper the test tube and shake.

The solution in test tube turned pink, so I interpreted that as a shift to the products. Also, a precipitate (proper term? a solid was present...) formed.

3. The Attempt at a Solution

Now I have to offer an explanation for why this occurred. It seems as though the Ag+ is slightly soluble in Cl-, and the Cl is found on the product side, so was the Cl consumed somehow and thus produced CoCl42-?

To me that doesn't seem reasonable.

EDIT: I somehow thought myself into a circle, because CoCl42- wouldn't have been produced, for if it had the solution should have turned blue right? I'm fairly sure my explanation should hinge on the fact that Ag+is only slightly soluble with Cl-, but I don't want to go off on a tangent either, so if I'm horribly misguided please advise.

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#### General_Sax

I'm using this thread as a sort of running journal. If that is unacceptable, for some reason, please do inform me.

New equation:

2AgNO3(s) + 6H2O(al) + 2CoCl4(al)2- <=> Co(h2O)6(al)2+ + 8Cl(al)- + Co(NO3)2 (al) + 2Ag (s) + energy

How many different ways can the equilibrium be shifted to the right? i.e. Removal of product, addition of reactant and removal of energy.

#### General_Sax

The charges on the new equation don't balance. Looks like more Co(H20)6 (al) 2+ will have to be produced, and if that holds true then I can explain the colour change.

#### Borek

Mentor
None of the reaction you have written so far is correct.

What happens in the solution containing Ag+ and Cl-?

#### General_Sax

None of the reaction you have written so far is correct.

What happens in the solution containing Ag+ and Cl-?

CoCl42- + 6HOH + 4AgNO3(s) <=> Co(HOH)62+ + 4AgCl(s) + 4NO3- + energy

Is this equation correct?

#### Borek

Mentor
Much better, but not necesarilly correct.

AgNO3 is well soluble. And no need to put some fancy looking dihydrogen monoxide HOH in the equation

#### General_Sax

Doesn't HOH = H2O? I just found it easier to type HOH, so I did. Thanks for the help.

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