The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 16
(2011) pp 85-88
Conductivity Sensor Determination of vanít Hoff Factor: A General Chemistry Laboratory Exercise
Frazier Nyasulu*, Phyllis Arthasery, and Rebecca Barlag
Department of Chemistry and Biochemistry, Ohio University,
Athens, OH 45701, email@example.com
Published: 18 March 2011
Abstract. This laboratory exercise describes conductivity measurements of solutions in the concentration range of 0.0010 M to 0.010 M using a datalogger and a conductivity sensor. These conductivities are used to determine the vanít Hoff factor, i, for NaCl(aq), Na2SO4(aq) and MgSO4(aq). Considering the fact that theoretical and experimental i differ because of ion pairing, it is concluded that (a) ion pairing increases with concentration, (b) ion pairing is particularly significant when ion charge magnitudes are greater than one.
Key Words: Laboratories and Demonstrations; general chemistry; laboratory instruction; solutions; conductivity; electrochemistry
(*) Corresponding author. (E-mail: firstname.lastname@example.org)
Supporting Materials:Two supporting files are available. A laboratory handout and Excel spreadsheet in a compressed zip file (443 KB).