Marjoram Extract as Corrosion Inhibitor for Dissolution of Zinc in 1.0 M HCl

Table 6

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

Inhibitor conc. (ppm)	𝑅𝑠; Ω cm²	𝑅ct; Ω cm²	𝐶dl; µF cm^−2	IE(𝑅) (%)
0.00	0.95	51	22.30	—
100	1.15	198	19.43	74.10
200	1.30	318	17.11	83.50
300	1.95	353	15.13	85.60
400	2.13	385	10.85	86.30
500	2.65	440	9.53	88.80