Explanation:
the answer and the working out is shown above, hope it helps.
According to this formula :
㏑[A] /[Ao] = - Kt
when we have Ao = 0.3 m
and K =0.46 s^-1
t = 20min = 0.2 x 60 =12 s
So by substitution :
㏑[A] / 0.3 = - 0.46 * 12
㏑[A] / 0.3 = - 5.52
by taking e^x for both side of the equation we can get [A]
∴[A] = 0.0012 mol dm^-3
One thing incorrect is that when dealing with a compound, such as H2SO4, that has 7 atoms in the chemical formula, the polyatomic ion SO4 doesn’t dissociate into one Sulfur and four Oxygens. SO4 stays and a PAI.