Quiz #1

Open Notes, Open Neighbor

On a piece of paper put your Name, Student ID Number and Answer to:

Find the rate constant for the reaction:

[Ni(H2O)6]2+(aq) + NH3(aq) → [Ni(H2O)5(NH3)]2+(aq) + H2O(l)

Where the reaction is first order in [Ni(H2O)6]2+ and zero order in NH3, the initial concentration of all reactants are 1 M, and the half-life of the reaction was found to be 2000 s.

Possibly useful information:

Zero order: t½ = [A]o/2k

First order: t½ = 0.693/k

Second order: t½ = 1[A]ok

Answer

The total order of reaction is 1 so the first order equation can be used:

Solving for k gives k = 0.693/t½

k = 0.693/2000 = 3×10–4 s–1.