Enthalpy Change of Reaction & Formation - Thermochemistry & Calorimetry Practice Problems

TL;DR

Learn how to calculate enthalpy change and heat transfer in reactions using formulas and specific heat capacities.

Transcript

in this video we're going to focus on how to calculate the enthalpy change of a reaction so consider the combustion reaction of ethanol c2h5oh in the combustion reaction you have a hydrocarbon which usually reacts with o2 the products of a combustion reaction is always going to be co2 and water now go ahead and pause the video and balance the react... Read More

Key Insights

• 🙃 Balancing combustion reactions involves ensuring the same number of atoms on both sides, starting with carbon, then hydrogen, and finally oxygen.
• 👻 Hess's law allows the calculation of the enthalpy change of a reaction by adjusting and combining balanced equations and summing the enthalpies of the individual reactions.
• 💁 Enthalpy change of formation is the same as the enthalpy of a reaction where a compound is produced from its elements in their natural state.
• 😆 Heat transfer in reactions can be measured using calorimetry, which involves a calorimeter and the formula q = mcΔt.
• 💱 Phase changes involve conversions between solid, liquid, and gas states, with specific heat capacities and enthalpy changes associated with each process.

Summary & Key Takeaways

• The video explains how to balance a combustion reaction and calculate the enthalpy change of the reaction using the heats of formation for each substance.

• Hess's law is introduced as a method to estimate the enthalpy change for reactions by adjusting and combining balanced equations.

• Enthalpy of formation is defined as the enthalpy change of a reaction where one mole of a compound is produced from its elements in their natural state.

• Calorimetry is discussed as a way to measure heat transfer in reactions by using the equation q = mcΔt and converting between joules and kilojoules.

• Phase changes (freezing, melting, vaporization, condensation, sublimation, and deposition) are explained, along with whether they are endothermic or exothermic processes.