Catalysts and Reaction Mechanisms

The video tutorial explains how to draw complete reaction diagrams, focusing on potential energy, delta H, and activation energy. It discusses the role of catalysts in lowering activation energy and speeding up reactions. A demonstration with hydrogen peroxide illustrates these concepts in action.

What does the y-axis represent in a reaction diagram?

• Time

• Potential energy

• Reaction progress

• Temperature

What is the significance of the 'hump' in a reaction diagram?

• It represents the total energy of the products.

• It indicates the energy required to start the reaction.

• It shows the energy released during the reaction.

• It marks the equilibrium point of the reaction.

How is the delta H of a reaction calculated using Hess's Law?

• By adding the energies of reactants and products.

• By dividing the energy of products by the energy of reactants.

• By subtracting the energy of reactants from the energy of products.

• By multiplying the energies of reactants and products.

What is the primary function of a catalyst in a chemical reaction?

• To increase the temperature of the reaction.

• To increase the pressure of the reaction.

• To lower the activation energy required.

• To change the products of the reaction.

Which of the following is NOT an example of a catalyst?

• Sodium iodide

• Potassium permanganate

• Enzymes

• Water

What happens to the activation energy hump when a catalyst is added?

• It becomes smaller.

• It disappears completely.

• It becomes larger.

• It remains unchanged.

In the demonstration, what role does yeast play in the reaction with hydrogen peroxide?

• It is an inhibitor.

• It acts as a reactant.

• It serves as a catalyst.

• It is a product of the reaction.

What is the result of adding soap to the catalyzed reaction in the demonstration?

• It slows down the reaction.

• It captures oxygen gas as bubbles.

• It increases the temperature of the reaction.

• It changes the color of the reaction.

What is the main observable effect of a catalyst on the reaction rate?

• The reaction rate becomes unpredictable.

• The reaction rate increases.

• The reaction rate decreases.

• The reaction rate remains the same.

What is the purpose of using a catalyst in the hydrogen peroxide demonstration?

• To increase the amount of hydrogen peroxide.

• To speed up the decomposition of hydrogen peroxide.

• To change the products of the reaction.

• To prevent the reaction from occurring.