Corrosion Inhibition Effect of 4-Hydroxy-N′-[(E)-(1H-indole-2-ylmethylidene)] Benzohydrazide on Mild Steel in Hydrochloric Acid Solution

Table 3

Electrochemical impedance parameters for the corrosion of mild steel in 1 M HCl in the absence and presence of inhibitor at different temperatures.

Temp. (°C)	Conc. of HIBH (mM)	(Ω cm^2)	(μF cm^−2)		% IE
30	0	15.70	1785	0.705	—
	0.1	89.55	84.31	0.732	82.5
	0.2	96.64	67.50	0.753	83.7
	0.4	101.5	64.19	0.757	84.5
	0.6	115.1	54.61	0.763	86.3
	0.8	122.0	50.58	0.766	87.1
40	0	9.63	3761	0.765	—
	0.1	60.07	207.4	0.767	83.9
	0.2	62.10	166.3	0.778	84.5
	0.4	66.39	141.2	0.795	85.4
	0.6	71.74	121.3	0.799	86.5
	0.8	76.35	94.24	0.817	87.3
50	0	5.00	12936	0.773	—
	0.1	31.99	540.4	0.768	84.3
	0.2	33.75	450.1	0.778	85.1
	0.4	36.35	401.1	0.788	86.2
	0.6	40.47	350.3	0.795	87.6
	0.8	42.5	289.8	0.82	88.2
60	0	1.90	55870	0.742	—
	0.1	13.41	2333.8	0.756	85.8
	0.2	13.81	2158.4	0.762	86.2
	0.4	14.86	1945.8	0.794	87.2
	0.6	15.90	1709.0	0.807	88.0
	0.8	18.55	1304.7	0.82	89.7