[noorie123]

CuO (s) + H⁺(aq) + CL^-(aq)  CuCl₂*2H₂O (s)

I tried on my own and i managed to put a 2 infront of Cl  but i am confused about the dihydrate... Should there be a 2 infront of CuO also, since it is 2H20 on the right side? and a 4 infront of H, since its 2H2 on the right which makes 4?

Am i thinking right?

[Arkcon]

This reaction is unbalanced, because atoms appear on the right, that don't appear on the left, specifically O for oxygen.  Now, before you start adding it as a reactant, lets try to work with this a bit.  You've got the states of matter included, right.  You're reacting a solid, with two ions dissolved in water.  Do you really get a solid product?

[noorie123]

Its from a lab that im doing, We are mixing CuO in HCl and some water... will then evaporate to get the salt.

[Arkcon]

Yeah.. and I made an oops, there is oxygen on both sides.  OK.  You start with a solid and and aqueous solution of acid.  You get, after drying, a hydrated salt.  But the dry hydrated salt doesn't just appear, you have to do another step to dry it.  So separate those steps.

[noorie123]

CuO (s) + H+(aq) + CL-(aq)  cu²⁺(aq)+2Cl^-(aq)+H₂O


Like this?

[XeLa.]

Yes, that looks good. That would be the step which actually occurs due to mixing the two chemicals. However, what do you this happens to the copper (II) chloride so that it forms a hydrate (the molecule with water attached)? What would the balanced equation be?

XeLa

[XeLa.]

*What occurs involving the CuCl₂ so that a hydrate forms?

P.s: Sorry, I wish this could be condensed with my above reply.

XeLa

[noorie123]

A 2 infront of Cl-  and H+ to balance it 


Not quite sure how the hydrate forms..

[Borek]

This is a bit tricky, as the reaction you wrote in the very first post mixes several things - solid CuO (which is OK, as it is always a solid), H⁺ and Cl^- (which suggests reaction taking place in the solution), and CuCl₂·2H₂O(s) (which suggests the reaction doesn't take place in the solution). So as you see the original reaction equation contradicts itself, making it difficult to decide how it really should like. Plus, there is no way to balance it as written (not because of mixing solids and ions, just not every combination of substances produces equation that can be balanced).

The best approach would be to write two separate reaction equations: one for CuO dissolution if the solution of HCl (with Cu²⁺ being on the products) and second of the drying of the copper chloride solution.

Alternatively you can add water molecule on the left and see if you can balance the equation then. It won't make much chemical sense in terms of a single reaction taking place, but it will still nicely show the stoichiometry of a real process in which CuCl₂·2H₂O is produced by dissolving CuO in hydrochloric acid and crystallizing it out from the solution.

[Vidya]

CuO (s) + H+(aq) + CL-(aq)  cu²⁺(aq)+2Cl^-(aq)+H₂O

It is a simple acid base reaction

CuO (s) + 2H+(aq) + 2Cl-(aq)  ------> Cu2+(aq)+2Cl-(aq)+H2O

Just balance your H and Cl