Question

Soda lime that has changed color from purple to white:

a) Is depleted of CO2-absorbing capacity
b) Contains excess water vapor
c) Is overheated
d) Indicates a pH shift to alkaline

Answer 1

Soda lime changes color from purple to white to signal that its CO2-absorbing capacity is depleted, meaning it has reacted with enough CO2 and can no longer absorb more effectively. the correct answer is a) Is depleted of CO2-absorbing capacity.

Step-by-step explanation:

When soda lime changes color from purple to white, the correct answer is a) Is depleted of CO2-absorbing capacity. Soda lime is a mixture used to absorb carbon dioxide in systems such as rebreathing anesthesia circuits, respirators, or submarine air systems. As CO2 passes through soda lime, it reacts with the calcium hydroxide in the soda lime to form calcium carbonate.

This reaction depletes the CO2-absorbing capacity of the soda lime, and is typically indicated by a color change. Indicators like phenolphthalein are added to soda lime; these substances serve as a visual cue for pH changes that correspond to the saturation of the soda lime. When the material changes color, it suggests that the soda lime can no longer absorb CO2 effectively and needs replacing.