Exercise 10 | Chemical Kinetics: Rate Laws

Sample of oak from an ancient site have a carbon-14 content equal to 85.0 % that in living matter.

Estimate the age of the wood knowing that t1/2 (14C) = 5730 years.

Radioactive decay is a first-order process:

ln NN0 = -kt and t1/2ln 2k

⇒ ln NN0 = - ln 2 × tt1/2

⇒ t = ln N0N x t1/2ln 2 = ln (100/85) x 5730ln 2 = 1340 years