A system consists of carbon, C, oxygen, O2, and carbon dioxide, CO2 confined in a fixed volume, airtight, perfectly isolated container. For each of the descriptions below, indicate the type of state of the system.
(a) Measurements are made from time to time, and it is found that the amount of free oxygen is continuously decreasing.
(b) Measurements are made from time to time, and it is found that the amounts of C, O2, and CO2 are invariant. Moreover, it is found that upon igniting a spark, these amounts are affected.
(c) Measurements are made from time to time, and it is found that the amounts of C, O2, and CO2 are invariant. Moreover, despite many efforts, including igniting a spark, these amounts are not affected.
(d) Measurements of the energy of the system made from time to time show that the energy is time invariant.
