Using Reactions to Understand Chemistry: Examining CuI(s) Formation

AI Thread Summary
The discussion centers on a chemical reaction involving copper ions and iodide ions, specifically the reaction 2Cu2+(aq) + 4I-(aq) -> CuI(s) + I2(aq). It highlights a balancing issue, noting that the correct product should be 2CuI(s). The formation of CuI is explained through the reduction of Cu(+2) to Cu(+1) and the oxidation of I(-1) to I(0). Additionally, the low solubility of CuI is emphasized, which drives the reaction equilibrium to favor the formation of solid CuI. The context of back titrations and the use of excess iodide to remove silver ions is mentioned, clarifying the relevance of the reaction despite the initial confusion regarding the presence of Ag+. Overall, the discussion confirms the accuracy of the textbook's content, aside from the noted balancing error.
pivoxa15
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In my textbook, it had

2Cu2+(aq) + 4I-(aq) -> CuI(s) + I2(aq)

How does that work? First of all it's not balanced. It should be 2CuI(s). But how does CuI(s) form. It should be CuI+.

The book did say excess 4I- was usd to remove Ag+ since it was talking about back titrations. But the reaction as stated dosen't involve Ag. Has the book made mistakes?
 
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No, it's correct (except for the missing 2).

Cu(+2) is reduced to Cu(+1) and I(-1) is oxidized to I(0).
 
I see. Thanks
 
Note: this reaction is interesting as its equilibrium is moved to the right thanks to the very low solubility of CuI.
 

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