Unit D TOK Activity – Models, Reactions & Reliability

TOK Quiz: Chemistry in the Real World – Models, Reactions & Reliability

By Rosa Arredondo

​Emergency responders and military personnel often rely on chemical heating pads or self-heating meals (MREs) when they are deployed in harsh environments without access to traditional cooking or heating. These systems use exothermic reactions to generate heat instantly when water is added to a chemical compound, such as calcium chloride or magnesium. The chemistry behind this is reliable and predictable—but responders must trust that the heat produced will be safe, consistent, and effective, even in life-or-death situations.

​Simultaneously, the cold packs used to reduce swelling in sports injuries or accidents rely on endothermic reactions—absorbing heat from the body. In both cases, we rely on scientific models and laboratory-tested reactions to predict real-world performance.

TOK Knowledge Question

To what extent can we rely on scientific models and controlled experiments to produce knowledge that remains valid and trustworthy in unpredictable real-life conditions?

Multiple Choice

What type of chemical reaction occurs in a self-heating meal (MRE) when activated?

• Endothermic reaction

• Exothermic reaction

Multiple Choice

Why are cold packs useful in emergency first aid?

• They prevent infections

• They cause exothermic burns

• They absorb heat and reduce swelling

Multiple Choice

Which of the following is a challenge when applying lab-tested chemical reactions in real-life scenarios like emergency response?

• The reactions work faster outside the lab

• Environmental conditions may affect the outcome

• They never work in cold places

• Only physicists understand them

Multiple Choice

Why are models used in chemistry to explain exothermic and endothermic processes?

• They eliminate the need for experiments

• They allow scientists to test unpredictable events

• They simplify complex processes to support understanding and prediction

• They make experiments more artistic

Multiple Choice

What is a limitation of relying solely on controlled experiments to produce scientific knowledge?

• Experiments don’t require peer review

• Controlled conditions may not reflect real-life variability

• Experiments always fail when repeated

• Experiments are unnecessary in TOK

Open Ended

Explain how a self-heating meal demonstrates the use of scientific knowledge in real life.

Open Ended

In your opinion, can models be fully trusted to work in unpredictable real-world situations? Why or why not?