Naturally Occurring Elettaria cardamomum Extract as a Corrosion Inhibitor for the Dissolution of Zinc in 1.0 M HCl

Table 5

Impedance data and surface coverage for zinc electrode in 1.0 M HCl in absence and presence of different concentrations of inhibitor.

Inhibitor conc. (ppm)	𝑅𝑠  (Ω cm²)	𝑅ct  (Ω cm²)	𝐶dl  (μF cm^−2)	θ	IE (%)
0.00	0.95	51	22.30	—	—
100	1.20	230	19.80	0.78	77.80
200	1.42	345	17.33	0.85	85.20
300	2.02	378	15.47	0.86	86.50
400	2.30	418	11.08	0.87	87.80
500	2.85	470	9.78	0.89	89.20