Copper carbonate (also known as cupric carbonate) is a compound with the molecular CuCO3 and has a molar mass of 123. 5 g/mol. Its boiling point is 200oC, therefore it is a solid at room temperature. It is a blue-green compound often used in artist’s paint and some types of make-up. Copper carbonate, CuCO3, thermally decomposes and two reactions could take place: 2CuCO3(s) i?? Cu2O(s) + 2CO2(g) + 1/2O2(g) CuCO3(s) i?? CuO(s) + CO2(g) I will be using the moles theorem to calculate, which reaction takes place in the lab.
A mole of a solid substance is the mass, which contains the same number of particles as there are in 12g of carbon-12. This number is known as the Avogadro constant, L, which is i?? 6 x 1023 mol-1. It is important as we can use it to calculate how much of each substance is needed to produce a certain volume or mass of a substance, as I will be doing in this experiment. Furthermore, the theorem also dictates that one mole of any gas at room temperature and pressure occupies 24dm3.
So in the first equation, two moles of copper carbonate is needed to produce one mole of cuprous oxide, two mole of carbon dioxide and half a mole of oxygen gas. In the second equation, one mole copper carbonate is needed to produce one mole of cupric oxide and one mole of carbon dioxide. I will also be using the theory of relative atomic mass (RAM) to find out, which reaction takes place in the lab. The definition of relative atomic mass is the average mass of the naturally occurring isotopes of an atom, taking in to account relative abundance, compared to carbon-12 (which is exactly 12).
The molar mass (the mass of one mole) is the RAM in grams. By calculating the molar mass, and starting with a known mass of copper carbonate, I will be able to know how much gas will be produced in each case and therefore, which reaction takes place in the lab. Variables My independent will be the volume of gas produced during the reaction, as this is what I will be measuring, however I have no dependent variable as there is nothing that I am changing.