**Category:** Optics  
**Subtype:** Refraction and Total Internal Reflection  
**Problem Description:** This problem involves the behavior of light as it passes from one medium (liquid) to another (air) and the conditions for total internal reflection. Specifically, it asks for the critical angle that must be satisfied for total internal reflection to occur when light travels from the liquid back to the air. The goal is to determine the range of angles of incidence (i) that will lead to total internal reflection.