For a first-order reaction, A → B, the rate coefficient was found to be 3.4 × 10-4 s-1 at 23 °C. After 5.0 h, the concentration of A was found to be 0.00018 mol L-1. What was the original concentration of A?

the original concentration of A = 0.0817092  M

Explanation:

A reaction is considered to be of first order it it strictly obeys the graphical equation method.

where;

k = the specific rate coefficient  = 3.4 × 10⁻⁴ s⁻¹

t = time   = 5.0 h = 5.0 × 3600 = 18000 seconds

a = initial concentration = ???

a - x = remaining concentration of initial concentration at time t = 0.00018 mol L⁻¹

a = 0.0817092  M

Thus , the original concentration of A = 0.0817092  M

answer7,570,82356 cubic centimeters;