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

≈ 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

you didnt put any of the following

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally