What triggers a chemical reaction? - Kareem Jarrah

TL;DR

Enthalpy and entropy are two important factors in chemical reactions that determine whether a reaction will occur and how much energy will be released or absorbed.

Transcript

You know how sometimes you go to bake a cake but your bananas have all gone rotten, your utensils have rusted, you trip and pour all of your baking soda into the vinegar jug, and then your oven explodes? My friend, you and your chemical reactions have fallen victim to enthalpy and entropy and, boy, are they forces to be reckoned with. Now, your re... Read More

Key Insights

• 💱 Enthalpy is the change in energy during a chemical reaction and determines whether a reaction is exothermic or endothermic.
• ❓ Exothermic reactions release energy into the surroundings, while endothermic reactions absorb energy.
• ❓ Entropy measures the randomness of a chemical system and can facilitate reactions by transitioning from a more ordered structure to disorder.
• 💱 Enthalpy and entropy are essential in determining the likelihood and energy changes associated with chemical reactions.
• 🔠 Reactions that release energy (exothermic) are more likely to occur than reactions that require energy input (endothermic).
• 🥺 The collapse of an ordered structure leading to increased entropy can provide the instability needed for reactions to start.
• ✊ The energy released by exothermic reactions can power endothermic reactions.

Questions & Answers

Q: What is enthalpy and how does it influence chemical reactions?

Enthalpy is the change in energy during a chemical reaction. Molecules with more energy are less stable and more likely to react. This energy change determines whether a reaction is exothermic or endothermic.

Q: How are exothermic and endothermic reactions different?

Exothermic reactions release energy into the surroundings, resulting in a decrease in the chemical's final energy. Endothermic reactions, on the other hand, absorb energy, causing an increase in the chemical's final energy.

Q: What role does entropy play in chemical reactions?

Entropy measures the randomness of a chemical system. A shift towards higher entropy, such as the collapse of an ordered structure, can allow reactions to occur by providing the necessary instability for reactants to overcome the energy barrier.

Q: How do enthalpy and entropy work together in a real-life example?

Lighting a campfire demonstrates both enthalpy and entropy. The match provides the energy (enthalpy) to initiate the exothermic combustion reaction, while the randomness and chaos of the burning wood result in increased entropy, facilitating the reaction.

Summary & Key Takeaways

• Enthalpy is the change in energy during a chemical reaction, with more energy leading to less stability and a higher likelihood of reactions.

• Exothermic reactions release energy into the surroundings, while endothermic reactions absorb energy.

• Entropy measures the randomness of a chemical system, and a shift towards higher entropy can facilitate reactions.