Chemistry · University
Half-life of a first-order reaction · formula reference
This formula applies to a first-order rate law and not generally to zero- or second-order reactions.
Formula
This formula applies to a first-order rate law and not generally to zero- or second-order reactions.
t½ = ln 2/k
Worked example
A first-order reaction has k=0.6 min⁻¹. Find its half-life. Round the final result to 4 decimal places if needed. Answer in min.
Set the remaining fraction exp(−kt) to 1/2 and solve t=ln 2/k.
1.1552 min
Prerequisites and checking
Algebra and the topic definitions. Keep units and rounding consistent. State the model conditions before applying the formula.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
AI-assisted preview; independent educational review required. Level labels describe prerequisites, not accreditation or official curriculum alignment.