Table 5.

Thermodynamic adsorption parameters of (PdC-OH, PdC-Me and PdC-H) adsorbed on the carbon steel surface in 1 M HCl acid at various temperatures.

Inhibitor	Temp °C	$K_{\mathit{ads}}$ M−1	$-{\mathrm{\Delta }G}_{\mathit{ads}}$ kJ mol−1	$\mathrm{\Delta }{\text{H}}_{\mathit{ads}}^0$ kJ mol−1	$\mathrm{\Delta }{\text{S}}_{\mathit{ads}}^o$ J mol−1 K−1
PdC-OH	25	32,809.5	35.7 ± 0.2028	4.1	119.9 ± 0.2028
	30	36,934.9	36.6 ± 0.1732		120.9 ± 0.2333
	35	40,524.1	37.4 ± 0.1453		121.6 ± 0.1453
	40	53,827.7	38.8 ± 0.2028		123.9 ± 0.1453
PdC-Me	25	29,344.9	35.4 ± 0.1028	5.1	118.9 ± 0.1732
	30	36,488.6	36.5 ± 0.1732		120.8 ± 0.1453
	35	40,555.4	37.5 ± 0.2028		121.6 ± 0.2028
	40	67,268.9	39.5 ± 0.1453		125.8 ± 0.1764
PdC-H	25	25,750.7	35.3 ± 0.1732	4.2	117.9 ± 0.1453
	30	33,662.9	36.5 ± 0.2028		120.1 ± 0.1732
	35	33,759.1	37.3 ± 0.1732		120.1 ± 0.2028
	40	46,040.1	38.7 ± 0.1000		122. 7 ± 0.2309