Kajian termodinamik sel elektrokimia sistem seng - Perak oksida.

Abstract

Mempelajari konsep dasar termodinamika dapat dilaku¬kan melalui model elektrokimia. Menurut Smith dan Vin¬cent, sel elektrokimia seng-perak oksida dapat digunakan untuk keperluan tersebut. Penelitian bertujuan untuk membuktikan ketergantung¬an harga gaya gerak listrik terhadap temperatur dan menentukan harga-harga parameter termodinamik sel seng-perak oksida. Penelitian dilakukan dengan menerapkan metoda Smith dan Vincent. Perubahan gaya gerak listrik pada setiap temperatur diikuti memakai Multimeter Digital HC-81. Pengukuran dilakukan pada temperatur 10°C-70°C. Hasil penelitian menunjukkan bahwa harga gaya gerak listrik sel cenderung turun apabila temperatur naik, sesuai dengan Persamaan Nerst. Sedangkan perubahan energi bebas Gibbs, entalgi dan entropi reaksi hasil perhitungan padattemperatur 25 C bequrut-turut adalaki -304,121 kJ mol , -312,842 kJ mol dan -29,264 J aK mol', dekat dengan harga-harga pada literatur. Harga-harga parameter termodinamik dengan mengguna¬kan model sel elektrokimia sesuai dengan yang diperoleh melalui pengukuran panas oleh Hills menurut laporan Smith dan Vincent. The basic concepts of thermodynamic studies can be done via electrochemical models. According to Smith and Vincent, the electrochemical system as zink-silver oxide cell can be served for that purpose. The objectives of this research are establishing dependence of electromotive force values to the tempera¬ture and determining the thermodynamic parameters of zink-silver oxide battery. The Smith and Vincent method was applied to the experiment. The electromotive force change at each temperature variation was followed by Di¬gital Multimeter HC-81. The measurement was carried out at the temperature range of 10 - 70 C. The experiment results showed that the electromotive force values of battery cell tend to decrease as the tem¬perature increased; thus are in agreement with Nernst equation. Furthermore, the Gibbs free eneEgy, enthalpy and entropy changes that calculated at 25 C, respecti¬velylare =304.121 kJ mol-t, -312.842 kJ mol' and -29.264 J K mol , are quite similar to those from the litera¬ture. The values of thermodynamic parameters from the ex-periment based on electrochemical models are in agreement with the values from the heat measurement by Hill as re-ported by Smith and Vincent also. This document is Undip Institutional Repository Collection. The author(s) or cod iV , wner(s) agree that UNDIP-IR may, without changing the content, translr :le submission to any medium or format for the purpose of preservation. The author(s) or copyright owner(s) also agree that UNDIP-IR may keep more than one copy ui 4i-lis submission for purposes of security, back-up and preservation. ( http://eprints.undip.ac.id) it i