Question

the decay of chlorine in a distribution system follows first-order decay with a rate constant of 0.360 d21 . if the concentration of chlorine in a wellmixed water storage tank is 1.00 mg/l at time zero, what will the concentration be one day later? assume no water flows out of the tank.

Answer 1

Using the first-order decay formula, the concentration of chlorine one day later (given a decay rate constant of 0.360 day-1) is calculated to be approximately 0.6977 mg/L.

Step-by-step explanation:

To calculate the chlorine concentration after one day using the given first-order decay rate constant (0.360 day-1), we apply the first-order decay formula:

C = C0e-kt

Where C is the final concentration, C0 is the initial concentration, k is the rate constant, and t is the time in days.

In this case, with an initial concentration C0 of 1.00 mg/L, k = 0.360 day-1, and t = 1 day, we get:

C = 1.00 mg/L x e-(0.360)(1)

By calculating the exponent first:

e-(0.360)(1) = e-0.360 = 0.6977 (approximately)

Then multiply:

C = 1.00 mg/L x 0.6977 ≈ 0.6977 mg/L

So, one day later, the concentration of chlorine will be approximately 0.6977 mg/L.

Answer 2

The concentration of chlorine will be approximately 0.697 mg/l one day later.

Step-by-step explanation:

The decay of chlorine in a distribution system follows first-order decay with a rate constant of 0.360 d-1. To find the concentration of chlorine one day later, we can use the formula for first-order decay:

C(t) = C0 * e-kt

Where C(t) is the concentration at time t, C0 is the initial concentration, e is Euler's number (approximately 2.71828), k is the rate constant, and t is the time.

Plugging in the values, we have:

C(1) = 1.00 * e-(0.360)(1) = 0.697

Therefore, the concentration of chlorine one day later would be approximately 0.697 mg/l.