In the presence of excess thiocyanate ion, SCN-, the following reaction is first order in chromium (III) ion, Cr3+; the rate constant is 2.0 x 10-6/s.
What is the half-life in hours? How many hours would be required for the initial concentration of Cr3+ to decrease to each of the following values:
25%
12.5%
6.25%
3.125%