Exp2-chm171L - CHM171L / A11 Physical Chemistry Laboratory...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Y = 143.19 x – 0.165 CHM171L / A11 Physical Chemistry Laboratory 2 3 rd Quarter S.Y. 2010-2011 Conductimetry: Determination of the Electrical Properties of Solutions Austria, Maynard 1 , Co, Argenia B. 2 1 Professor, CHM171L/A31, School of Chemical Engineering, Chemistry and Biotechnology, Mapua Institute of Technology; 2 Student, CHM171L /A31 , School of Chemical Engineering, Chemistry and Biotechnology, Mapua Institute of Technology ABSTRACT The experiment mainly focused on Conductimetry, particularly in determination of electrical properties of certain solutions. The experiment aims to determine relative mobility of some monovalent ions through measuring the conductance of solutions of electrolytes, also to acquire dissociation constant of a weak electrolyte. The experiment was actually divide into two parts, and from part A (Electrolytic Conductance and Ionic Mobility) based from the values obtained, it is found that HCL has the highest conductance, followed by NaOH, NaCl, NH 4 Cl, and NaC 2 H 3 O 2 has the lowest conductance. For part B (Determination of dissociation constant of a weak electrolyte), the experiment used various concentration of KOH and water, from that the plot of concentration vs conductance enable the computation for dissociation constant of NH 4 OH at 1 M and O.01 M. also, from the graph it shows the conductance changes proportionally with the concentration. KOH was used since its concentration is equal to the concentration of Ammonia ionized in the solution. INTRODUCTION Conductimetry is concerned with the electrical conductivity of electrolytes. Measurements are made indirectly across the resistance of the solution with alternating current, since direct current would alter the composition of the sample solution by electrolysis. Conduction or electrical conduction is the mechanism by which charge flows or the movement of electrically charged particles through a transmission substance (electrical conductor). This movement of charge constitutes an electric current and the physical parameters governing this transport depend upon the substance. Therefore, conductivity (electrical conductivity or specific conductivity) is a measure of the ability of a substance to conduct an electric current. In solutions, current is carried by free moving ions (positive and negative). A conductive solution is known as an 'electrolyte' and includes solutions of ionic salts or of compounds that ionize in solution (e.g. acids and bases). Conductivity is the reciprocal (inverse) of electrical resistivity and has the SI units of siemens per metre (S•m -1 ). Electrical conductivity is commonly represented by the Greek letter . σ Experience has shown that for reasons related to the measuring technique (polarization phenomena) better results are obtained when the measuring frequency is adapted to the range of measurement. The conductivity of a solution depends on:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/31/2011 for the course CHE-CHM-BT CHM171L taught by Professor Calderon during the Spring '11 term at Mapúa Institute of Technology.

Page1 / 4

Exp2-chm171L - CHM171L / A11 Physical Chemistry Laboratory...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online