General Chemistry | Enthalpy of Reaction (ΔH_rxn) [Example 1]

In this video, Kevin Tokoph from Catalyst University explains how to calculate the enthalpy of reaction (delta H) using an example of glucose combustion. He discusses the importance of knowing the heats of formation for each species involved and explains the concept of standard states. The video provides a detailed calculation process, emphasizing the need to correctly handle coefficients and signs. The video concludes with a reminder to look up necessary data and a preview of future topics, including Hess's law.

What is the primary purpose of calculating the enthalpy of reaction?

• To calculate the pressure change in a reaction

• To find the overall energy change in a reaction

• To determine the speed of a reaction

• To measure the temperature change in a reaction

Why is the enthalpy of formation for oxygen gas considered zero?

• Because it is a liquid at room temperature

• Because it is not involved in the reaction

• Because it is in its standard state

• Because it is a noble gas

Which of the following is necessary to calculate the enthalpy of reaction?

• The color of the reactants

• The volume of the reaction container

• The enthalpies of formation of reactants and products

• The speed of the reaction

In the calculation of enthalpy of reaction, why is it important to use the correct phase of a substance?

• Because the phase affects the speed of the reaction

• Because the phase affects the enthalpy of formation

• Because the phase affects the pressure of the reaction

• Because the phase affects the color of the substance

What is the enthalpy of formation for glucose as a solid?

• -285.8 kJ/mol

• -393.5 kJ/mol

• -1,260 kJ/mol

• 0 kJ/mol

What is the final calculated enthalpy of reaction for the combustion of glucose?

• -2,815.8 kJ/mol

• -1,260 kJ/mol

• -4,075.8 kJ/mol

• -1,714.8 kJ/mol

Why is it important to remember the signs when calculating enthalpy of reaction?

• Because they affect the final enthalpy value

• Because they determine the color of the reaction

• Because they change the phase of the reactants

• Because they alter the speed of the reaction