Corrosion inhibitors represent the most cost effective and flexible means of controlling internal corrosion associated with oil and gas production. Tests were carried out to demonstrate the structure/effect relationships which are effective in controlling the inhibition efficiency. To illustrate this approach, the substituent field effect at the paraposition of 1(Benzyl)1‐H‐4,5‐Dibenzoyl‐1,2,3‐ Triazole (BDBT) on corrosion inhibition has been investigated. Mild steel rotating cylinder electrode in acid media was used in conjunction with Tafel polarization technique, AC impedance measurements and continuous linear polarization resistance method. The nitro group was found to cause a considerable decrease in the corrosion inhibition of the parent compound BDBT. Owing to the induction effects of Br on the aromatic ring the bromo derivative has better inhibition protection than the methyl derivative. The corrosion rate profiles obtained from on‐line polarization technique showed that the inhibition capacity of the studied substituents at the para‐position increases as follows: NO2 < CH3 < Br < H.

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The applications of direct current and mark-space biased square wave differential electrolytic potentiometry alongside zero-current potentiometry to single and mixed halide precipitation titrations with silver(I), to single halide precipitation or complexation titrations with mercury( I) and to single halide complexation titrations with mercury(I1) in anhydrous acetic acid media have been examined, using silver, silver amalgam and gold amalgam electrodes. Mercury(1) offers no advantage over silver, which gives excellent results for single halides, particularly with silver electrodes, and chloride and bromide mixtures are fully resolved in this medium as well as chloride and iodide, particularly with silver amalgam electrodes, while bromide and iodide titrate to total halide only : chloride, bromide and iodide mixtures are resolved, but not accurately. The mercury(I1) titrations are much improved in the anhydrous medium with respect to water ; gold amalgam electrodes are favoured .

The applications of direct current and mark-space bias square wave differential electrolytic potentiometric techniques to acidbase titrations in a n acetic anhydrideacetic acid mixed solvent have been examined. Antimony metalmetal oxide electrodes were used as indicating systems. Titration curve shapes are similar to those obtained from aqueous acidbase titrations, but the required current density and percentage bias are much higher. Several compounds that do not exhibit basic properties in water were titrated successfully with perchloric acid. The advantage of using an aprotic solvent in conjunction with acetic anhydride is demonstrated.

The application of direct current differential electrolytic potentiometry to acidbase titrations in toluenemethanol mixed solvent has been investigated. Antimony electrodes have been examined in titrations of diverse acids with sodium methoxide. Normal differentiation was observed only in the titration of weak acids. Malfunction of the anode in titration of stronger acids was reflected in the differential curves, a n d was accompanied h y ;I decrease in mass of the electrode. The zero-current antimony electrode exhibited similar behaviour with the strongest acids. The effect has been traced to a chemical reaction between methanol and the antimony oxide in the presence of stronger acids.