Question

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

Answer 1

Hint: To describe what happens in a particular chemical reaction, we have to write an equation for it. This begins with some written statement that can be used to form a word equation. This word equation contains the general structure of the equation, in that it consists of an arrow in the middle which separates the reactants from the products.

Complete answer:
When heated, solid copper \[{\text{(II)}}\] carbonate decomposes to solid copper \[{\text{(II)}}\] oxide and carbon dioxide gas. From this we can write word equation as follows:
Copper \[{\text{(II)}}\] carbonate $(s) \to $ Copper \[{\text{(II)}}\] oxide $(s) + $ Carbon dioxide $(g)$
Copper \[{\text{(II)}}\] carbonate and Copper \[{\text{(II)}}\] oxide are both ionic compounds. Carbon dioxide is a covalent molecule of oxygen and carbon atoms. When we translate this word equation into a chemical equation, we need not change the stoichiometric coefficients since it will already be balanced.
$CuC{O_3}(s)\xrightarrow{\Delta }CuO(s) + C{O_2}(g) \uparrow $
This reaction is balanced with respect to charge and mass. Most of the carbonates undergo this decomposition reaction if we supply enough heat to the reaction. A color change from green to black is observed during the reaction.
Therefore, the chemical equation that describes the decomposition of solid copper \[{\text{(II)}}\] carbonate to solid copper \[{\text{(II)}}\] oxide and carbon dioxide gas is $CuC{O_3}(s)\xrightarrow{\Delta }CuO(s) + C{O_2}(g) \uparrow $

Note:
Some chemical compounds breakdown when they are heated, forming two or more products from one reactant. This type of reaction is called thermal decomposition. Many metal carbonates take part in thermal decomposition reactions.