The rate constant for a reaction is 5.55 × 10^-3s^-1.If after 4 minutes you have 44.1g of material left,what was the initial concentration?

Question

Quizplus · Accepted Answer

We can use the integrated rate law for a first-order reaction to solve for the initial concentration:

ln([A]/[A]o) = -kt

where [A] is the concentration at time t, [A]o is the initial concentration, k is the rate constant, and t is the time elapsed.

Plugging in the given values, we get:

ln(44.1g/[A]o) = -(5.55 × 10^-3 s^-1)(4 min)(60 s/min)

Simplifying, we get:

ln(44.1g/[A]o) = -1.656

Solving for [A]o, we get:

[A]o = 167 g

Therefore, choice C is the correct answer.

The Rate Constant for a Reaction Is 5