Decomposition of cooper II carbonate hydroxide hydrate.

[zimbob]

Homework Statement

Lab Experiment:
I added 5g of Cu2CO3(OH)2 in a bunsen burner and the resultant was a black product weighing 3.327g, representing a mass ratio of 0.67/1.0

Homework Equations

The question is whether the remaining black compound is anhydrous copper carbonate hydroxide molecule (Cu2CO3(OH)2 whose molecular weight is 221.116g/mol while that of water is 18.015 g/mol.

What would be the equation for the decomposition of copper carbonate hydroxide hydrate ( I will try to balance it myself).

The Attempt at a Solution

I believe its CuO but how can show that its not?

 

[chemisttree]

You first must assume that you know the purity of your starting material. The amount of pure copper carbonate hydroxide is therefore = (purity)*(mass of Cu(II)(CO3)(OH)2).

From there calculate the number of moles of the carbonate-hydroxide given and the expected mass of the product(s). Which one is closer to the data given in the problem?

 

[zimbob]

Thanks for your reply.
The purity of the starting material was not provided but however your lead has put me in better shape. Any hint on the decomposition equation?

 

[chemisttree]

You have several choices. The point of the problem is to point you to the correct answer. Let's see what you have in some detail and we can discuss it further.