Inhibition Effect of 1-Butyl-4-Methylpyridinium Tetrafluoroborate on the Corrosion of Copper in Phosphate Solutions

Table 7

Thermodynamic adsorption parameters for copper in 0.5 M PO⁴³⁻ solutions in the presence of 10.0 mM of 1-Butyl-4-methylpyridinium tetrafluoroborate (4MBPBF₄) for pH 2 and 4 at different temperatures.

pH	Temperature (K)	𝐾×10^−2; (𝑀^−1)	Δ𝐺^0ads; (kJ mol^−1)	Δ𝐻^0ads; (kJ mol^−1)	Δ𝑆^0ads; (J mol^−1 K^−1)
2	303	1.71	−22.69	−16.69	20.14
	313	1.39	−22.17		18.40
	323	1.12	−21.65		16.65
	333	0.93	−21.20		15.15
	343	0.79	−20.78		13.74
4	303	2.86	−23.97	−19.27	15.76
	313	2.29	−23.41		13.91
	323	1.79	−22.80		11.84
	333	1.44	−22.26		10.04
	343	1.18	−21.78		8.42