[orgo814]

The data below apply to the reaction: (CH3)3CBr + H2O yields (CH3)3COH + HBr. Determine order of the reaction.
T/min: 0   3.15   6.20   10.00   18.30   30.80
[(CH3)3CBr]/(mol/L): 10.39   8.96   7.76   6.39   3.53   2.07

Don't have excel to confirm at the moment so I reasoned it was second order because the half life of initial (half life of 10.39) is around 5 and then the half life of half the initial (second half life) increased more than twice that amount so there seems to be an inverse relationship between concentration and t. Is this correct?