Thermodynamics and Energy Diagrams: Crash Course Organic Chemistry #15

What type of chemical is responsible for almost all the smells we perceive?

• Inorganic compounds

• Organic chemicals

• Noble gases

• Metallic elements

What does a negative change in enthalpy (ΔH) indicate about a chemical reaction?

• The reaction absorbs heat from its surroundings.

• The reaction releases heat to its surroundings.

• The reaction increases in entropy.

• The reaction is non-spontaneous.

What does a negative value for Gibbs free energy (ΔG) signify about a chemical reaction?

• The reaction requires external energy to proceed.

• The reaction is spontaneous.

• The reaction is at equilibrium.

• The reaction decreases in entropy.

In an energy diagram, what does the x-axis typically represent?

• The temperature of the reaction.

• The change in enthalpy.

• The reaction progress.

• The concentration of reactants.

What characteristic defines an endothermic reaction?

• It releases heat into the surroundings.

• It requires heat to flow in to form products.

• Its products have lower energy than its reactants.

• It has a negative change in enthalpy (ΔH).

What does activation energy (Ea) represent in a reaction progress diagram?

• The total energy released during the reaction.

• The energy difference between reactants and products.

• The minimum energy required to start a chemical reaction.

• The energy of the products after the reaction is complete.

Based on the energy diagram for carbocation formation, which type of carbocation is more stable?

• Primary carbocation, because it has a higher activation energy.

• Secondary carbocation, because it has a lower activation energy.

• Primary carbocation, because it forms slower.

• Secondary carbocation, because it requires more energy to form.

How does a catalyst affect a chemical reaction?

• It increases the overall energy of the products.

• It is consumed during the reaction to form new products.

• It lowers the activation energy, speeding up the reaction.

• It shifts the equilibrium position towards the reactants.