(to get 3H2 on left). [ 3H2 + 1.5O2 → 3H2O \quad ΔH = -857.4 , \textkJ ]
(since we want ethanol as product, not reactant). [ 2CO2 + 3H2O → C2H5OH + 3O2 \quad ΔH = +1367 , \textkJ ] 1972 ap chemistry free response answers
For decades, the Advanced Placement (AP) Chemistry exam has been the gold standard for high school college-level chemistry. While modern students focus on quantum mechanics and organic spectroscopy, the 1972 exam represents a fascinating "retro" challenge—a test built in an era of slide rules, log tables, and heavy emphasis on stoichiometry, equilibrium, and descriptive chemistry. (to get 3H2 on left)
ΔH°f (C2H5OH, l) = -277.4 kJ/mol
By: AP Curriculum Historians