Enthalpy of Reaction

The video covers the enthalpy of reaction, explaining how energy is absorbed or released during chemical reactions. It discusses Alfred Nobel's use of nitroglycerin and the invention of dynamite. The video explains bond energy, endothermic and exothermic reactions, and introduces Hess's Law and enthalpy diagrams. It also covers the Born-Haber cycle and demonstrates problem-solving using Hess's Law to calculate enthalpy changes.

What is the primary focus of the enthalpy of reaction?

• The color change during a reaction

• The physical state of the reactants

• The speed at which a reaction occurs

• The amount of energy released or absorbed during a chemical reaction

In an endothermic reaction, how does energy flow?

• Equally between the reaction and surroundings

• From the surroundings into the reaction

• There is no energy flow

• From the reaction to the surroundings

What happens to the sign of enthalpy change when a reaction is reversed?

• It becomes positive

• It becomes negative

• It remains the same

• It doubles

What is the Born-Haber cycle used to illustrate?

• The physical state of products

• The steps in a reaction and their enthalpy changes

• The color change in a reaction

• The speed of a reaction

According to Hess's Law, what is the enthalpy of a reaction equal to?

• The sum of the enthalpies of the products

• The sum of the enthalpies of the reactants

• The sum of the enthalpies of all steps in the reaction

• The difference between the enthalpies of products and reactants

What is the first step in applying Hess's Law to solve for enthalpy change?

• Measure the physical state of reactants

• Identify the target reaction

• Calculate the speed of the reaction

• Determine the color change

How can you manipulate equations to find the overall enthalpy change?

• By changing the physical state of reactants

• By reversing and scaling equations

• By altering the color of products

• By measuring the speed of the reaction