Half Life for Second Order Reactions

[Ashish Verma 2I]

Why is it that for First Order Reactions the time required for the reaction to go to one fourth remaining is double the half life, but this is not true for second order reactions, as in problem 7B13 from the 7th edition?

[Chem_Mod]

Because for 2nd order reactions the half life depends on the initial concentration.

[Nico Medina]

I was wondering this too, thanks for the help!

[Katie Shi 1F]

For a 1st order reaction, the half-life is constant and independent of initial conditions (hence why [A]₀ is not in the half-life equation). For 0th and 2nd order reactions, the half-life is dependent on initial conditions (hence why [A]₀ are in the half-life equations).