Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Reference texts: Felder, Rousseau & Bullard, Elementary Principles of Chemical Processes (4th ed., Wiley) — psychrometric (humidity) mass balances with recycle, fuel/air combustion stoichiometry, and waste-heat sensible-energy balances; Smith, Van Ness, Abbott & Swihart, Introduction to Chemical Engineering Thermodynamics (8th ed., McGraw-Hill) — the van der Waals equation of state with one-fluid mixing rules and the reaction-equilibrium constant from standard Gibbs energies; critical-property data from Poling, Prausnitz & O’Connell, The Properties of Gases and Liquids (5th ed.).
Paper structure. 16-CHEM-A1, May 2019, three hours, open book. Part A (Process Mass and Energy Balances) has three questions and Part B (Chemical Thermodynamics) has three. The printed numbering restarts at 1 in Part B, and the cover note reads “Part B (Questions 4 and 6)”. Candidates answer TWO questions from each part; four questions make a complete paper, each of equal value. All six questions are worked below, labelled A1–A3 and B1–B3.
