# Homework Help: Decomposition of cooper II carbonate hydroxide hydrate.

1. Dec 9, 2007

### zimbob

1. The problem statement, all variables and given/known data

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

2. Relevant 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).

3. The attempt at a solution
I believe its CuO but how can show that its not?

2. Dec 10, 2007

### 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?

3. Dec 10, 2007