# Problem: If a solution containing 26.0 g of a substance reacts by first-order kinetics, how many grams remain after three half-lives?

🤓 Based on our data, we think this question is relevant for Professor Schultz's class at OSU.

###### FREE Expert Solution

Recall that half-life is the time needed for the amount of a reactant to decrease by 50% or one-half. One way to determine the amount remaining after x half-lives is:

$\overline{){\left[A\right]}_{\mathbf{t}}\mathbf{=}\frac{{\left[A\right]}_{\mathbf{0}}}{{\mathbf{2}}^{\mathbf{x}}}}$

where [A]t = concentration after x half-lives, [A]0 = initial concentration and x = number of half-lives.

We’re given [A]0 = 26.0 g and x = 3 half-lives. Solving for [A]t:

###### Problem Details

If a solution containing 26.0 g of a substance reacts by first-order kinetics, how many grams remain after three half-lives?