: This book has been through six editions, with the 6th Edition (2021) containing critical updates on industrial data, modern unit operations, and digital computation that earlier "free" versions will lack.
Stoichiometry by and S. M. Vora (now often co-authored with S. B. Thakore ) is a cornerstone textbook in chemical engineering. The Risks of Unofficial "Free" Downloads
: Modern editions include the use of mathematical software like Mathcad, MATLAB, and Scilab to solve complex stoichiometric problems.