Seek help in calculating the specific heat of the gases constituting the conversion system

Bro, the calculation of specific heat capacity has a large error; usually it’s due to some details that aren’t correct. I also made mistakes when working on the sulfur-based acid production project; here are three directions for investigation: Check the sources of the specific heat data for each component – the specific heat of SO2, SO3, O2, and N2 varies with temperature and is not a constant. It is recommended to use polynomial fitting formulas (such as those in the appendix of \"Chemical Engineering Thermodynamics\" or NIST data), rather than using the values at room temperature. In particular, SO3 decomposes easily at high temperatures; therefore, the appropriate temperature range must be selected for the data. Mixing rule: mole fraction or mass fraction? Generally, the molar fraction-weighted average specific heat at constant pressure is used (Cp = Σ yi * Cpi), but if mass fractions are used, the result will differ significantly. Furthermore, if the conversion system involves reactions, it is necessary to consider the effect of reaction heat on the effective specific heat (for example, the adiabatic temperature rise cannot be calculated using merely the mixture specific heat). Unit conversion and reference temperature: Check whether the specific heat unit you are using is kJ/(kmol·K) or kJ/(kg·K); there is a factor of molecular weight difference between the two. Also, when calculating the enthalpy change, whether to use 0°C or 25°C as the reference temperature can result in cumulative errors. If there is still a long way to go after the above checks, it is recommended to post the specific calculation steps so that everyone can help verify them. After all, in chemical engineering calculations, even a 1% difference is significant; double-checking several times ensures accuracy.