Diffusimetry Renounces Graham’s Law, Achieves Diffusive Convection, Concentration Gradient Induced Diffusion, Heat and Mass Transfer

Abstract

Absolute diffusion rates of KMnO₄ in vertical and flattened diffusimeters show the concentration gradient force as being stronger than the gravitational force. Hot water molecules move downward on self-diffusion against buoyancy. Diffusive convection (DC) in warm water and double-diffusive convection (DDC) in warm, saline water take place inside the diffusimeter with DDC transferring more heat than DC. In the diffusing medium the original reagents change or retain their compositions to give the diffusate molecules to diffuse. In water, the change is mostly hydration. The syngener BaCl₂.2H₂O separately with congeners 3CdSO₄.8H₂O, ZnSO₄.7H₂O, and ZnSO₄.H₂O presents two distinct pairs of overlapping concentration versus rate curves, first for having very close MWs of BaCl₂ and CdSO₄ and second for having ZnSO₄.H₂O as the common congener for both the zinc sulfates. Chlorides of Li, Na, and K diffusing at hindered rates in glucose solution show the least rate for LiCl inevitably on grounds of low mass and high Li⁺ hydration radius. Diffusion blocking occurs at higher glucose concentration. Diffusion of 0.6M AgNO₃-0.6M NH₄Cl standardizes this diffusimeter. Mass transfer of HCl, H₂SO₄, and H₂C₂O₄ show oxalic acid diffusing as hydrate and 88 percentage transfer of sulfuric acid in 5 minutes. The Superdiffusive Anti Graham’s Law, V_d ∝√M , is further consolidated by Ca (NO₃)₂-M₂CO₃(M = Na, K, NH₄⁺) and Ca (NO₃)₂-Na₂HPO₄ diffusions. Odd and even diffusions are illustrated by AgNO₃-NH₄Cl and AgNO₃-BaCl₂ diffusions.