-1
$\begingroup$

I'm pretty new to chemistry and came across a last year's chemical olympiad in our country and I got stuck on this (I tried googling this problem but after a half of hour I gave up):

Will these reactions occur? If they do, what will be the products?

$$\ce{H2S + CuCl2 -> ???}$$

$$\ce{H2S + KCl -> ???}$$

In my opinion, the copper will replace the hydrogen, but I'm pretty sure the potassium won't. Am I even correct? And what's the reason behind it?

Your help is really appreciated!

$\endgroup$
1
$\begingroup$

Here some hints

  1. Copper and sulphur will react to form $\ce{CuS}$ and $\ce{HCl}$. The equation needs to be balanced!

I'll let you check both copper (II) sulphide and copper (II) chloride solubility in water. It might lead you to a justification for the products.

  1. Second one, no reaction.

You can make analogous reasoning for the second equation.


Some extra thoughts

In both cases: Can we understand this behaviour microscopically? Why $\ce{CuS}$ has such a low solubility compared to $\ce{CuCl2}$

Copper and sulphur ions have similar size and sulphur higher electric charge than chloride ion. So we can undestand microscopically why $\ce{CuS}$ is less soluble than $\ce{CuCl2}$.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.