Canadian Entry To Practice (CETP) Practice Test 2025 - Free CETP Practice Questions and Study Guide

The product of incomplete combustion of propane that is known for having a pungent odor is aldehydes. When propane does not burn completely, several byproducts can be produced, and aldehydes are among them. These compounds often have strong, distinctive odors that can be perceived as unpleasant or pungent, which makes them notable in terms of safety and detection in combustion processes.

In contrast, while other compounds listed may arise from incomplete combustion, they do not share the same characteristic of possessing a notably pungent smell. Carbon dioxide, for instance, is a colorless and odorless gas that does not have a detectable scent. Soot, being a form of carbon released during combustion, can cause a smoky smell but is not widely recognized for its pungency in the same way aldehydes are. Carbon monoxide, a dangerous and odorless gas, poses significant health risks but lacks any odor, meaning it is not detectable by smell at all—making aldehydes the correct choice in this context.