[qwaszx]

Hi

   What are the units of k1 and k2 in:

-dln[(H2O)5CrCl2+]/dt = k1 + k2/[H+]

I think k1 = k2 = 1/s

What are the units of q and r in:

-d[V3+]/dt = (q/(r + [H+]))[V3+][Cr2+]

So  this reaction is second order (variational with respect to [H+] as seen above). Since they constitute k and k has units of 1/Molarity x seconds, r can = 1/(mol/L) and q can = 1/seconds. I think this choice of units makes sense...

[H+] can be ignored each time because the reactions vary between an order of -1 and 0 depending on [H+].

Sorry if my rational is totally wrong. I'm trying to teach myself kinetics and maybe am not doing the best job.

Thanks!

[Borek]

What are the units of k1 and k2 in:

-dln[(H2O)5CrCl2+]/dt = k1 + k2/[H+]

I think k1 = k2 = 1/s

Impossible - if k1 and k2 have the same units, k1 and k2/[H+] would have different units, and you will be not able to add them.

[qwaszx]

Okay, so [H+] cannot be ignored because while the reaction order with respect to H+ changes with [H+], the written equation deals with the chromium species. So, k1 = 1/s and k2 = (mol x liter)/s? So then r = mol per liter and q = 1/s?