HW#15.87

[Peter Dis1G]

Don't get what the question is asking. I only know that the slow step determines the reaction rate.

[Anna Goldberg 2I]

15.87 asks what conditions can be used to distinguish the two mechanisms-essentially, what mechanisms can be used to distinguish the two slow steps.
If the reaction is carried out in a highly concentrated solution of sucrose, mechanism ii will behave as a pseudo-first order reaction, due to its dependence on water. Mechanism i will occur at a rate independent of water and completely dependent on sucrose.
If the reaction is carried out in a very diluted solution, you will be unable to distinguish between the two mechanisms, as mechanism ii will behave as a pseudo-first order reaction with dependence solely on sucrose, and the concentration of water won't change.
This question revolves around the concept of pseudo-first order reactions and the consequences of having one reactant at a very high concentration.

[Nickolas Manipud 1C]

How do we know that ii) at high sucrose concentration is first order?