Question

When heated, solid copper(II) carbonate decomposes to solid copper(II) oxide and carbon dioxide gas. What is the chemical equation (including phases) that describes this reaction?

Answer 1

`CuCO_3(s) + Delta rarr CuO(s) + CO_2(g)uarr`

Explanation:

This reaction is balanced with respect to mass and charge; as indeed it must be if it reflects chemical reality. Most carbonates undergo this decomposition, provided you supply enuff heat to the reaction.

Typically, we would fiercely heat the copper carbonate in a vessel whose outflow was bled into a solution of limewater, `Ca(OH)_2(aq)`. The liberated carbon dioxide would react with the calcium hydroxide to form a carbonate:

`Ca(OH)_2(aq) + CO_2(g) rarr CaCO_3(s)darr + H_2O(l)`

If you were careful, you would see a fine white precipitate of calcium carbonate form in the second flask.