Certified Biomedical Equipment Technician (CBET) Practice Exam 2026 – Comprehensive All-In-One Guide for Exam Success!

When soda-lime absorbs carbon dioxide (CO2), it undergoes a chemical reaction that typically results in a noticeable change in its color. Soda-lime is a mixture of sodium hydroxide and calcium oxide, which can absorb CO2, leading to the formation of sodium carbonate and calcium carbonate. During this process, certain types of soda-lime may contain indicators that change color in response to the pH shift or the formation of carbonates, making it a valuable tool in various applications, especially in medical settings where CO2 absorption is essential for the efficacy of anesthesia machines or other respiratory equipment.

The other options do not accurately describe the behavior of soda-lime when it absorbs CO2. It does not evaporate, as it is a solid compound that undergoes a chemical change rather than a physical one. It also does not melt since soda-lime is stable at typical operating temperatures and does not change from a solid to a liquid state upon absorption of CO2. Additionally, while there might be some slight volumetric changes due to the formation of additional materials, the primary and most recognized change is the color change rather than a significant increase in volume.