Which term corresponds to a material that will spontaneously ignite upon exposure to atmospheric oxygen?

Which term corresponds to a material that will spontaneously ignite upon exposure to atmospheric oxygen?

• A. Disproportionation
• B. Oxidizer
• C. Peroxide Forming
• D. Pyrophoric

Answer: (D)

Materials that ignite on contact with air do so because they undergo rapid oxidation with atmospheric oxygen without needing an external flame or heat source. This instant, self-heating reaction is what defines a pyrophoric substance. In practical terms, handling these materials requires inert or oil-blanketed storage and avoidance of air exposure to prevent spontaneous ignition. Disproportionation is a redox process within a single species that yields two species with different oxidation states, not about ignition in air. An oxidizer is a substance that helps other materials burn by providing oxygen, but it does not necessarily ignite itself upon exposure to air. Peroxide forming describes materials that can form peroxides over time, which is a storage hazard, but it does not specify spontaneous ignition on contact with atmospheric oxygen.

Materials that ignite on contact with air do so because they undergo rapid oxidation with atmospheric oxygen without needing an external flame or heat source. This instant, self-heating reaction is what defines a pyrophoric substance. In practical terms, handling these materials requires inert or oil-blanketed storage and avoidance of air exposure to prevent spontaneous ignition.

Disproportionation is a redox process within a single species that yields two species with different oxidation states, not about ignition in air. An oxidizer is a substance that helps other materials burn by providing oxygen, but it does not necessarily ignite itself upon exposure to air. Peroxide forming describes materials that can form peroxides over time, which is a storage hazard, but it does not specify spontaneous ignition on contact with atmospheric oxygen.