Answer: C) a redox reaction that produces an electric current
Explanation:
Chemical cell is a device which is used for the conversion of the chemical energy produced in a redox reaction into the electrical energy. The cell consists of the negative terminal called as anode where oxidation takes place and a positive terminal called as cathode where reduction takes place.
Electrolytic cell is a device which is used to carry out chemical reactions by the use of electrical energy. The cell consists of the negative terminal called as cathode where reduction takes place and a positive terminal called as anode where oxidation takes place.
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