3: Thermal decomposition

decomposition

Chemical reaction in which a compound breaks down to form more than one product

thermal decomposition

Chemical reaction in which a compound breaks down from heating to form more than one product

What is the decomposition reaction of hydrogen peroxide?

* hydrogen peroxide → water + oxygen

What happens in the thermal decomposition reaction of copper carbonate?

* Copper carbonate is green compound made of copper carbon and oxygen
* When heated, it breaks down to form copper oxide and carbon dioxide
* Copper oxide is black and remains in test tube
* Carbon dioxide is a gas

How do you check if the gas produced is carbon dioxide?

If you bubble it through limewater, and it turns milky, it is CO2

What are type of carbonate that decompose from heating (including the reactants and products)?

* lead carbonate → carbon dioxide + lead oxide
* zinc carbonate → carbon dioxide + zinc oxide

How do you know, from reading a word equation, whether something is a decomosition reaction or not?

The product is simpler than the starting substance and has atoms of smaller numbers and more elements

word equation for decomposition reaction of magnesium nitrate

magnesium nitrate → magnesium oxide + nitrogen dioxide + oxygen

Describe the decomposition reactions of the nitrates of the Group 2 elements as you go down the group.

As you go down Group 2, the elements become more thermally stable and therefore requires more heat to decompose.

State a general rule to predict the products of the thermal decomposition reactions of the Group 2 elements’ nitrates.

The nitrates decompose to make an oxide of the Group 2 metal, as well as nitrogen dioxide and oxygen gases.