$$\ce{Cu2S + 2 O2 -> 2 CuO + SO2}$$
Why are not these oxides $\ce{Cu2O}$, $\ce{SO}$ or $\ce{SO3}$? Is it connected to the stability of these molecules?
Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. It only takes a minute to sign up.
Sign up to join this community$$\ce{Cu2S + 2 O2 -> 2 CuO + SO2}$$
Why are not these oxides $\ce{Cu2O}$, $\ce{SO}$ or $\ce{SO3}$? Is it connected to the stability of these molecules?
The reaction gives different products when combusted at different temperature.
Copper(I) sulfide react with oxygen to produce copper(I) oxide, copper sulfate and sulfur dioxide. This reaction takes place at a temperature of 500-600°C.Here
Copper(I) sulfide react with oxygen to produce copper(I) oxide and sulfur dioxide. This reaction takes place at a temperature of 1200-1300°C.Here
Sulfur monoxide is very unstable and it is unlikely to exist in Earth's atmosphere but it exist in interstellar spaces. Sulfur trioxide will not form from sulfur dioxide as it requires an oxidising agent.
Right reaction is $$\ce{2Cu2S + 3O2 -> 2Cu2O + 2SO2}$$
$\ce{Cu2O}$ is because copper in this compound has oxidation state +1 and $\ce{2Cu + O2 -> 2CuO}$.
$\ce{SO2}$ is because $\ce{SO}$ is unstable and $\ce{S + O2 -> SO2}$.
Upd. This answer isn't right. See comments of @Jan under it.