Warning: Be careful where you download from. Many "free" educational sites have outdated versions (5th or 6th edition) with missing chapters or typos.
Here are the best legitimate sources:
This is where heat and work are quantified. The slides distinguish between heat transfer (driven by temperature difference) and work (force times distance). Look for the slides covering "Boundary Work" ($W_b = \int P , dV$), which is notoriously tricky for sophomores. thermodynamics cengel ppt
Before you can study, you need the files. There are typically two types of PPTs associated with this textbook: Warning: Be careful where you download from
Every Cengel chapter ends with a summary slide (often 2-3 slides). The night before your exam, rewrite this summary from memory. Compare it to the PPT. The gaps are what you need to study. Every Cengel chapter ends with a summary slide