Reactive substances may cause which undesired effects?

• A. No hazards are expected under any condition.
• B. Undesirable effects such as pressure buildup, temperature increases, or the formation of noxious, toxic or corrosive by products, may occur due to reactions to heating, burning, direct contact with other materials, or other conditions.
• C. Only beneficial byproducts are produced.
• D. Reactions occur only at extremely high temperatures and are always safe.

Answer: (B)

Reactive substances can release energy and form hazardous products when they encounter heat, flame, friction, direct contact with other materials, or other conditions. This can lead to pressure buildup in confined spaces, temperature increases that may accelerate the reaction or cause burns, and the formation of noxious, toxic, or corrosive byproducts. These possibilities are why safe handling, separation, and storage are crucial in any environment where reactive materials are present.

This idea is captured by the statement that undesired effects such as pressure buildup, temperature rises, or toxic/corrosive byproducts may occur due to reactions under various conditions. The other ideas—that no hazards occur, that only beneficial byproducts are produced, or that reactions only happen at extremely high temperatures and are always safe—do not reflect real-world chemical behavior and safety considerations.