Enthalpy of Formation Reaction & Heat of Combustion, Enthalpy Change Problems Chemistry

Summary

This tutorial covers how to write chemical reactions for enthalpy of formation and combustion, and provides step-by-step methods for calculating enthalpy changes using product and reactant values.

Highlights

Writing Formation Reactions00:00:01

Explanation of how to write formation reactions, where the substance must have a coefficient of one on the right, while elements in their natural states appear on the left.

Standard Enthalpy of Formation00:02:55

Explanation that the enthalpy of formation for elements in their natural state is zero, making the reaction enthalpy equal to the formation heat of the product.

Writing Combustion Reactions00:03:48

Guidelines for writing combustion reactions by adding oxygen (O2) and balancing products to yield carbon dioxide and water, maintaining a one-mole coefficient for the substance being burned.

Calculating Enthalpy Change of Reaction00:06:44

Introduction to the formula using standard heats of formation: enthalpy of reaction equals the sum of products minus the sum of reactants, accounting for molar coefficients.

Determining Enthalpy of Combustion00:09:29

Applying the products-minus-reactants formula to calculate the specific heat of combustion for liquid ethanol.

Calculating Unknown Enthalpy of Formation00:13:00

Method to solve for an unknown enthalpy of formation value within a chemical equation by using the given total enthalpy change of the reaction.