Some Thiophene Derivatives as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid

Table 5

Thermodynamic parameters for the adsorption of inhibitors on carbon steel surface in 1 M HCl at different temperatures.

Inhibitor	Temperature (°C)	𝐾ads.× 10^−3	−Δ𝐺^∘ads.	Δ𝐻^∘ads.	Δ𝑆^∘ads.
		(M^−1)	(kJ mol^−1)	(kJ mol^−1)	(kJ mol^−1)
A	25	42.8	36.4	2.8	0.13
	35	36.9	37.2		0.12
	45	57.1	39.6		0.12
	55	139.4	43.3		0.13
B	25	30	35.5	1.7	0.12
	35	43.2	37.6		0.12
	45	58.8	39.7		0.12
	55	57.1	40.8		0.12
C	25	13.4	33.5	3	0.12
	35	14.9	34.9		0.11
	45	16.5	36.3		0.11
	55	46	40.2		0.12