Document Type

Thesis - Open Access

Award Date

1965

Degree Name

Doctor of Philosophy (PhD)

Department

Agronomy

Abstract

The recent development of practical cation-sensitive glass electrodes prompted the writer to investigate the feasibility of their application to the monitoring of nutrient-cation activities in natural soils. It soon became evident that the nature of the suspension effect must be more clearly understood if such application were to yield meaningful results. The suspension effect may be defined as the pH of solution in equilibrium with a suspension minus the pH of the suspension, both pH values being measured potentiometrically. Two theories have been advanced to explain the cause of the suspension effect: the observed pH difference is real, the observed pH difference is largely an illusion. The suspension effect is an error caused by a liquid junction potential at the boundary between the saturated KCL salt bridge and the suspension. If theory (1) is correct, then potentiometric measurements on soil systems can be interpreted in terms of ionic activities. If theory (2) is correct, however, such interpretation is subject to error. The purpose of the present study was to devise experimental means of distinguishing between theories (1) and (2) or assessing the importance of each.

Library of Congress Subject Headings

Colloids
Chemistry, Physical and theoretical

Description

Includes bibliographical references

Format

application/pdf

Number of Pages

60

Publisher

South Dakota State University

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