Anticorrosive efficacy and adsorptive study of guar gum with mild steel in acidic medium

Journal of Analytical Science and Technology

Table 5 Parameters for the adsorption of guar gum on mild steel surface at 304 and 313 K temperature

		304 K						313 K
Applied isotherm	Medium	Cont. (ppm)	Time (hours)	B	Kads (ppm⁻¹)	R²	ΔGads (kJ mol⁻¹)	B	Kads (ppm⁻¹)	R²	ΔGads (kJ mol⁻¹)
Langmuir adsorption isotherm	1N HCl	250	6	−5.81	363.6	0.95	−25.05	−7.365	373.6	0.82	−25.12
		500	24	−5.97	314.7	0.93	−24.68	−5.026	315.9	0.94	−24.69
		750	48	−4.56	299.48	0.92	−24.56	−5.782	306.3	0.95	−24.61
		1000	72	−9.87	314.16	0.96	−24.68	−10.19	317.4	0.96	−24.70
Langmuir adsorption isotherm	1N H₂SO₄	250	6	−11.03	332.24	0.94	−24.82	−11.98	342.3	0.97	−24.90
		500	24	−9.39	322.65	0.99	−24.75	−26.32	439.6	0.98	−25.53
		750	48	−12.91	348.93	0.99	−24.94	−16.41	377.4	0.96	−25.14
		1000	72	−27.26	416.58	0.99	−25.39	−10.61	334	0.95	−24.83
Langmuir adsorption isotherm	1N HNO₃	250	6	36.25	340.67	0.97	−24.88	42.72	347.1	0.93	−24.93
		500	24	68.21	274.95	0.99	−24.34	73.67	276.8	0.98	−24.36
		750	48	162.4	515.44	0.89	−25.93	202.5	501.5	0.95	−25.86
		1000	72	266.5	577.21	0.86	−26.22	343.5	568.1	0.92	−26.18