Final answer:
A runaway reaction is a chemical process that accelerates out of control, leading to rapidly increasing temperature and pressure, and often a hazardous situation. It is different from a spontaneous reaction, which occurs naturally and favors product formation, as runaway reactions result from a positive feedback loop where the reaction's energy furthers its own progression.
Step-by-step explanation:
What is a Runaway Reaction?
A runaway reaction is a chemical process that once initiated, continues to accelerate out of control, usually resulting in the rapid increase in temperature, pressure, or both. This kind of reaction can occur if the rate of heat produced by the reaction exceeds the rate at which the heat can be removed from the reaction system. When a reaction becomes runaway, it typically implies that a positive feedback loop is in place where the reaction provides the energy to further drive itself. This can often lead to hazardous situations in industrial processes such as chemical manufacturing.
The term runaway greenhouse effect specifically refers to a similar uncontrollable process in a planet's climate system, where the greenhouse effect, responsible for warming a planet's surface, becomes so strong that it leads to an uncontrollable and escalating rise in temperature. This is a concern for climate change studies as a potential future scenario where Earth could experience an extreme and irreversible change in climate due to amplified global warming.
Spontaneous reactions, on the other hand, are those that occur naturally and favor the formation of products under the given conditions. An example of a spontaneous reaction is a bonfire, which is exothermic, releasing heat, and leading to an increase in entropy as the products largely consist of gases like carbon dioxide and water vapor. However, when these reactions become unmoderated and extreme, they may transition into a runaway process.