ExxonMobil Process Engineer interview questions

The interview session was great, and the panel was very friendly. But this is just the first session, still waiting for the second interview. Regarding the question, it just a basic question for a process engineer.

Interviewers were friendly and process was very smooth. First round was with junior supervisors and second round was with department heads (senior supervisors). Once you have cleared the first round, you would be notified for the second round wthin a couple of weeks