Question

The rate constant of a first order reaction is 0.035 sec-1. How much of a 1.5 M sample of reactant would remain after 28 seconds

Answer 1

0.56 M

Step-by-step explanation:

Step 1: Given data

• Rate constant (k): 0.035 s⁻¹

• Initial concentration of the reactant ([A]₀): 1.5 M

• Time elapsed (t): 28 s

Step 2: Calculate the amount of reactant ([A]) after 28 seconds

For a first-order kinetics, we will use the following expression.

ln [A] = ln [A]₀ - k × t

ln [A] = ln 1.5 - 0.035 s⁻¹ × 28 s

[A] = 0.56 M