Finding a complete, official "solucionario" (answer key) for Rolando Álvarez's 6300 Problemas de Química Básica
Si no consigues el solucionario, no todo está perdido:
Mateo sat in the corner of the university library, the air smelling of old floor wax and desperation. He was on Problem #2,417—a complex equilibrium calculation that seemed designed to make him quit engineering before he’d even started. "You're doing it the 'academy' way," a voice whispered.
The spine of the book was held together by more clear tape than paper. On the cover, the name Rolando Alva Alvarez
The Importance of Problem-Solving in Chemistry