Question

the reaction constant k is 9.23'10?3ms and [nh3]=0.851 when t=0 seconds. what is the concentration of nh3 at t=15.0 seconds?

Answer 1

To calculate the NH₃ concentration at t = 15.0 seconds, assuming a first-order reaction, use the formula [A]t =
`[A]0e^{-kt` with the initial concentration and the reaction constant. The estimated concentration of NH₃ at 15.0 seconds is 0.740 M.

Step-by-step explanation:

To determine the concentration of NH₃ at t = 15.0 seconds, we need to first confirm the order of the reaction, which is not provided in the question, unfortunately. Assuming it is a first-order reaction based on provided context, the concentration at time t can be calculated using the integrated rate law for a first-order reaction:

[A]t = [A]0e-kt

Where:

• [A]t is the concentration of NH₃ at time t,
• [A]0 is the initial concentration of NH₃ ,
• k is the reaction constant, and
• t is the time (in seconds).

For the given values:

• [A]0 = 0.851 M
• k = 9.23 × 10-3 s-1
• t = 15.0 s

We get:

[A]t = 0.851 × e-(9.23 × 10-3)(15.0)

Calculating this gives:

[A]t ≈ 0.851 × e-0.13845 ≈ 0.851 × 0.870 ≈ 0.740 M

Thus, the concentration of NH₃ at 15.0 seconds is approximately 0.740 M.