The compound with the formula Cu2SO3 is called copper(I) sulfite. It is composed of copper ions with a +1 charge and sulfite ions with a -2 charge, resulting in the formula Cu2SO3.
The balanced equation for the thermal decomposition of copper(II) sulfite (CuSO3) into copper(I) oxide (Cu2O) and sulfur dioxide (SO2) is: 2CuSO3(s) → Cu2O(s) + SO2(g) + O2(g)
Oh, isn't that just a delightful chemical reaction we have here! When copperI sulfide is partially roasted in the presence of air, it forms copperI sulfite. Then, with a bit more heat, the copper sulfite breaks down into copperI oxide and sulfur. Just like painting a happy little tree, each step in the reaction brings us closer to a beautiful final result.