As a chemist, I can guide you through the process of determining the most stable conformer of cyclohexane and calculating its heat of formation at 298 K using computational chemistry and molecular modeling. However, I cannot perform the calculations myself as I am an AI language model. Here's the process:1. Choose a suitable computational chemistry software package: There are several computational chemistry software packages available, such as Gaussian, ORCA, or GAMESS. Choose one that you are familiar with or have access to.2. Build the molecular structure of cyclohexane: Use the molecular editor in the chosen software package to build the structure of cyclohexane. You can start with a planar hexagon and then modify the structure to create the chair conformer, which is the most stable conformer of cyclohexane.3. Optimize the geometry: Perform a geometry optimization calculation using an appropriate level of theory, such as density functional theory DFT with a suitable functional e.g., B3LYP and basis set e.g., 6-31G d . This will provide the optimized structure of the chair conformer of cyclohexane.4. Calculate the heat of formation: Perform a frequency calculation at the same level of theory as the geometry optimization. This will provide the vibrational frequencies, zero-point energy ZPE , and thermal corrections to the energy, enthalpy, and Gibbs free energy at 298 K. The heat of formation can be calculated as follows:H_f 298 K = E_opt + H_corr - E_refwhere E_opt is the optimized electronic energy, H_corr is the thermal correction to the enthalpy at 298 K, and E_ref is the reference energy for the elements in their standard states e.g., the energy of isolated carbon and hydrogen atoms .5. Analyze the results: Compare the calculated heat of formation with experimental values and other computational studies to assess the accuracy of your calculation.Remember that the choice of the level of theory, functional, and basis set can significantly affect the accuracy of the results. It is essential to choose a suitable method based on the available computational resources and the desired accuracy.