Question

The initial concentration of reactant in a first-order reaction is 0.27 M. The rate constant for the reaction is 0.75 s−1. What is the concentration (mol/L) of reactant after 1.3 s? The initial concentration of reactant in a first-order reaction is 0.27 . The rate constant for the reaction is 0.75 . What is the concentration () of reactant after 1.3 ? 0.72 0.10 2.5 0.029 1.7

Answer 1

Answer:

0.10 M

Explanation:

Given data

• Initial concentration of the reactant ([A]₀): 0.27 M

• Rate constant (k): 0.75 s⁻1

• Time (t): 1.3 s

• Concentration at time t ([A]): ?

For a first-order reaction, we can find the concentration of the reactant at a certain time using the following concentration vs. time expression.

$[A]=[A]_{0}.e^{-k\times t}$

$[A]=0.27M.e^{-0.75s^{-1} \times 1.3s}$

$[A]=0.10M$

Answer 2

Answer:

≈ 0.10M

Explanation:

[A]o = 0.27M

Rate constant, k = 0.75 s−1

[A] = ?

time, t = 1.3

Integrated formular for a first order reaction is given as;

ln[A] = ln[A]o − kt

ln[A] = ln(0.27) - 0.75(1.3)

ln[A] = -1.309 - 0.975

ln[A] = -2.284

[A] = 0.1019M ≈ 0.10M