The method of continuous variation (often referred to as Job’s method) is an easy and common method for the determination of the reactant stoichiometry of chemical equilibria. The traditional interpretation of Job plots has been limited to complex association equilibria of the type nA + mB ⇌ AnBm, while little focus has been placed upon displacement type reactions (e.g., A + B ⇌ C + D), which can give Job plots that look quite similar. We developed a novel method that allows the user to accurately distinguish between 1:1 complex association, 2:2 complex association, and displacement reactions using nothing more than a pocket calculator. This method involves preparing a Job plot of the system under investigation (using regularly spaced mole fractions), normalizing the measured quantities (such as the concentration of AnBm or C for the above reactions) to their maximum value (i.e., at mole fraction 0.5), and determining the sum of the normalized values. This sum is then compared with theoretically predicted...

Getting More out of a Job Plot: Determination of Reactant to Product Stoichiometry in Cases of Displacement Reactions and n:n Complex Formation

Microfluidic paper-based chip platform for benzoic acid detection in food.

An organocatalytic enantioselective conjugate addition of aryl methyl nucleophiles to a wide range of α,β-unsaturated aldehydes is developed.

A Strategy Enabling Enantioselective Direct Conjugate Addition of Inert Aryl Methane Nucleophiles to Enals with a Chiral Amine Catalyst under Mild Conditions

The role of solvent in the stepwise electrochemical oxidation of nickelocene to the nickelocenium dication

Organic solid state reactivity

Evaluation of ε for p-dinitrobenzene—aniline complexes by the Scott equation. Failure of the Benesi—Hildebrand equation

Nanogram detection of m-dinitroaromatics and their derivatives A re-evaluation of the spot-test based on the janovsky reaction.

Fresh evidence for proposed zwitterionic intermediates.

Anion-exchange initiation of reactions: Detection and spectrophotometric determination of aliphatic amines with 2,4-dinitrophenylhydrazine.

A systematic study of the chromatographic behavior or 43 metal ions has been carried out in Acetone-Formic Acid systems on thin layers of Silical Gel G. The separation potential of these systems has been investigated for numerous metal ions and a number of useful and interesting separations have been predicted. The results obtained have been discussed and analysed.

Pushkin M. Qureshi

Papers

Evaluation of ε for p-dinitrobenzene—aniline complexes by the Scott equation. Failure of the Benesi—Hildebrand equation

Nanogram detection of m-dinitroaromatics and their derivatives A re-evaluation of the spot-test based on the janovsky reaction.

Fresh evidence for proposed zwitterionic intermediates.

Anion-exchange initiation of reactions: Detection and spectrophotometric determination of aliphatic amines with 2,4-dinitrophenylhydrazine.

Chromatographic Behavior of 43 Cations on Silica Gel G in Acetone-Formic Acid Systems