ERIC Number: EJ1442802
Record Type: Journal
Publication Date: 2022-Nov
Pages: 5
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
EISSN: EISSN-1938-1328
Available Date: N/A
pH Chemohydrodynamic Patterns Modulated by Sodium Polyacrylate in the Bromate-Sulfite-Ferrocyanide Reaction System
Ling Yuan; Chunxiao Meng; Huiyu Hou; Hongzhang Wang; Changwei Pan; Juan Ma; Chenghao Zhu; Qingyu Gao
Journal of Chemical Education, v99 n11 p3805-3809 2022
Nonlinear chemical reactions produce interesting chemohydrodynamic patterns in an unstirred medium, which act as interesting demonstrations to display the novel phenomena in a nonequilibrium chemical system. Here, we report new outreach experiments: pH chemohydrodynamic patterns modulated by sodium polyacrylate in the bromate-sulfite-ferrocyanide (BSF) reaction system. In an unstirred Petri dish, transient pH stripe patterns for a bromate-sulfite-ferrocyanide reaction system driven by proton autocatalysis and isothermal density-induced flow can be initiated in the center of approximately two-dimensional Petri dishes by adding a small amount of sulfuric acid solution with a certain concentration. Finally, the transient patterns are restored to the homogeneous high pH state due to proton negative feedback. The addition of sodium polyacrylate can not only lead to horizontal Marangoni flow for forming filamentary pH patterns but also decreases the diffusion of hydrogen ions, which results in a monotonic relationship between the pattern lifetime and polyacrylate concentration. Through these simple, lively and interesting experimental demonstrations, undergraduate students majoring in chemistry can realize the effect of transportations such as diffusion, density-induced flow, and Marangoni flow on complex pattern formation driven by a simple inorganic clock reaction.
Descriptors: Chemistry, Scientific Concepts, Science Education, Science Experiments, Kinetics, Undergraduate Study, College Science, Pattern Recognition
Division of Chemical Education, Inc. and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A
Author Affiliations: N/A