ERIC Number: EJ1444830
Record Type: Journal
Publication Date: 2023-Jun
Pages: 9
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
EISSN: EISSN-1938-1328
Available Date: N/A
Dissolution of Calcium Hydroxide in Water: A Guided Inquiry in University and High School Chemistry Laboratories
Shun Iwasaki; Satoki Kodani; Yuto Zushi; Mito Hotta; Masami Hara; Tomoyuki Tatsuoka; Nobuyoshi Koga
Journal of Chemical Education, v100 n6 p2402-2410 2023
In this laboratory experiment, a guided inquiry exploring the physicochemical principles of the dissolution of Ca(OH)[subscript 2](s) in water is proposed for laboratory classes in university and high school. As part of students' inquiry, two experimental approaches are used. One is the change in solubility with temperature revealed by measuring the pH values of the suspended solution of Ca(OH)[subscript 2](s) at various temperatures, which is then extended to its thermodynamic relationship via examining the temperature dependence of the solubility constant. The other method is to determine the enthalpy of solution using the calorimetric measurements. Due to the poor solubility of Ca(OH)[subscript 2](s), for determining the enthalpy of the Ca(OH)[subscript 2](s) solution, development of an energy diagram composed of several paths of a reaction that involve the dissolution of Ca(OH)[subscript 2](s) as a component process and using Hess's law are essential. A combination of these experimental approaches yields a stepwise students' inquiry for revealing the source of the changes in Ca(OH)[subscript 2](s) solubility with temperature, which may be flexibly adapted as an appropriate program depending on the targeted students. The two experimental procedures are presented by critically examining the experimental results. Based on the results of educational practices, typical guided inquiry constructions suited for the university and high school chemistry courses are proposed.
Descriptors: College Science, Secondary School Science, Science Education, Science Laboratories, Chemistry, Laboratory Experiments, Scientific Concepts
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; Secondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A
Author Affiliations: N/A