Answer:
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