Reaction Mechanisms and Processes

Which of the following best describes a reaction mechanism?

In a proposed reaction mechanism, what term describes a species that appears in one step but is consumed in a later step, and therefore does not appear in the overall balanced equation?

In the context of chemical reactions, what does the collision theory primarily explain?

According to collision theory, what are the two primary factors that determine whether a collision between reactant molecules will lead to a successful reaction?

What is the role of activation energy in a chemical reaction?

Which statement is true regarding the relationship between bond breaking and bond forming in a chemical reaction?

What is the significance of an 'activated complex' in a chemical reaction?

How does increasing the temperature generally affect the rate of a chemical reaction, according to the principles discussed?

Which of the following is a key factor in determining the speed of a chemical reaction?

Consider the elementary steps of a reaction mechanism. What is the classification of a reaction where all reactants and products exist in the same phase?

A chemist proposes a multi-step reaction mechanism. What type of experimental evidence would be most useful in determining the probable sequence of these steps?

For the elementary reaction $A + B \rightarrow C$, which of the following molecular orientations would likely be most effective in leading to product formation, assuming A and B react through specific sites?

The reaction $2H_2(g) + O_2(g) \rightarrow 2H_2O(l)$ is exothermic, yet it does not occur spontaneously at room temperature. Why?

In an energy diagram for a chemical reaction, what does the 'activation energy' correspond to?

Consider a reaction coordinate diagram. What does a higher activation energy for a reaction indicate about the reaction rate?

What happens to the kinetic energies of molecules as temperature increases, according to kinetic-molecular theory?

Consider a reaction with an activation energy ($E_a$) of 50 kJ/mol. If the energy of the reactants is 20 kJ/mol, and the energy of the products is -10 kJ/mol, what is the energy of the activated complex?

For a reversible reaction, what is the relationship between the activation energy for the forward reaction ($E_{a,forward}$) and the activation energy for the reverse reaction ($E_{a,reverse}$) in an exothermic reaction?

Given the reaction $I_2(g) \rightleftharpoons 2I(g)$, which represents the first step of a possible reaction mechanism for the formation of HI. If the forward reaction is endothermic, how would you describe the change in enthalpy?

In a reaction coordinate diagram, the difference in energy between the reactants and the products is known as what?

How does the addition of a catalyst affect the activation energy of a reaction?

What is the primary reason why only a fraction of collisions between reactant molecules lead to a chemical reaction, even when they have sufficient energy?

Which of the following statements accurately reflects bond energies in relation to the stability of molecules?

If a reaction mechanism involves multiple steps, what is the rate-determining step?

How can the enthalpy of a reaction ($\Delta H$) be determined from the activation energies of the forward ($E_{a,forward}$) and reverse ($E_{a,reverse}$) reactions?