Question

If the decomposition of reactant A follows first-order kinetics, what concentration of A remains if:

[A]0 = 0.273 M, k = 1.53 ∗ 10⁻² minutes⁻¹, and the elapsed time = 1.61 hr?

Answer 1

The concentration of reactant A remains approximately 0.108 M.

Step-by-step explanation:

In a first-order reaction, the concentration of reactant A decreases exponentially with time. The rate equation for a first-order reaction is given by:

[A] = [A]o * e^(-kt)

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

Using the given values: [A]o = 0.273 M, k = 1.53 * 10^(-2) minutes^(-1), and the elapsed time = 1.61 hours = 96.6 minutes.

Plugging these values into the equation:

[A] = 0.273 * e^(-1.53 * 10^(-2) * 96.6)

[A] ≈ 0.108 M