Conductivity of Electrolyte Solutions

Better Essays
Experiment 4: Conductivity of electrolyte solutions
(Dated: October 29, 2009)

I.

INTRODUCTION

Pure water does not conduct electricity, but any solvated ionic species would contribute to conduction of electricity. An ionically conducting solution is called an electrolyte solution and the compound, which produces the ions as it dissolves, is called an electrolyte. A strong electrolyte is a compound that will completely dissociate into ions in water. Correspondingly, a weak electrolyte dissolves only partially. The conductivity of an electrolyte solution depends on concentration of the ionic species and behaves differently for strong and weak electrolytes. In this work the electric conductivity of water containing various electrolytes will be studied. The data will be extrapolated to infinitely dilute solutions and the acidity constant for a given weak electrolyte will also be determined. Additional theoretical background for electrolyte solutions can be found from Refs. [1–3].
II. THEORY

Movement of ions in water can be studied by installing a pair of electrodes into the liquid and by introducing a potential difference between the electrodes. Like metallic conducting materials, electrolyte solutions follow Ohm’s law: R= U I (1)

where R is the resistance (Ω, “ohms”), U is the potential difference (V, “Volts”), and I is the current (A, “Amperes”). Conductance G (S, Siemens or Ω−1 ) is then defined as reciprocal of the resistance: G= 1 R (2)

Conductance of a given liquid sample decreases when the distance between the electrodes increases and increases when the effective area of the electrodes increases. This is shown in the following relation: G=κ A l (3)

where κ is the conductivity (S m−1 ), A is the cross-sectional area of the electrodes (m2 ; e.g. the effective area available for conducting electrons through the liquid), and l is the distance between the electrodes (m). Molar conductivity Λm (S m2 mol−1 ) is defined as: Λm = κ c (4)

where c is the



References: [1] P. W. Atkins and J. de Paula, Physical Chemistry (7th ed.) (Oxford University Press, Oxford, UK, 2002). [2] R. J. Silbey, R. A. Alberty, and M. G. Bawendi, Physical Chemistry (4th ed.) (Wiley, New York, 2004). [3] R. Chang, Physical chemistry for the chemical and biological sciences (University Science Books, Sausalito, California, 2000). 12

You May Also Find These Documents Helpful

  • Good Essays

    electrical conductivity of electrolytes and non-electrolytes activity demonstrated the physical propertiesand the conductivity of some solution. Electrical conductivity apparatusare dipped into a liquid in a beaker. Whenthe liquid contains significant concentrations of ions, the ions more between the electrodes to complete the circuit(which includes a light bulb).Tapwater and distilled water are examples of non-electrolytes. A solution of a weakelectrolytes, acetic acid (CH3COOH), 5% sucrose solution; it…

    • 693 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Conductivity Solutions Lab

    • 1056 Words
    • 5 Pages

    Conductivity Solutions Abstract: We produced conductivity tests in water and other various solutions with a computer faced Conductivity Probe using the unit of microsiemens per centimeter (uS/cm) to find out which solutions had a high conductivity and which solutions had a low conductivity. Many different solutions vary in conductivity due to the ratio of ions. Different levels of ions have an impact on conductivity because of the different charges and different types of bonds. Conductivity is…

    • 1056 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Electrolytes

    • 1066 Words
    • 5 Pages

    EXPERIMENT Ion - an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons. Ionization - The condition of being dissociated into ions by heat, electrical discharge, radiation, or chemical reaction. Electrolyte - A chemical compound that ionizes when dissolved or molten to produce an electrically conductive medium. Dissociation - When an ionic compound breaks up into its ions. The experiment started by placing the rods of the light bulb device into…

    • 1066 Words
    • 5 Pages
    Good Essays
  • Better Essays

    Conductivity Lab

    • 1614 Words
    • 7 Pages

    Using the information provided in the Introduction and your observations from Part 1, hypothesize as to the type of electrolyte the following solutions would be. Justify the hypothesis from a chemical standpoint. a. Aqueous Sodium Hydroxide—NaOH (aq) is a very strong base, which will completely disassociate into Na+ and OH- ions, which would make it a very strong electrolyte. Chemical reaction of the disassociation of Sodium Hydroxide: NaOH (aq)Na+ (aq)+ OH-(aq) b. Aqueous NaCl—Sodium Chloride…

    • 1614 Words
    • 7 Pages
    Better Essays
  • Good Essays

    Electrolytes

    • 830 Words
    • 4 Pages

    The blood plasma is consists of electrolytes. It comprise of both negative and positive charge. The negative charge is made up of chloride, bicarbonate and phosphates. The positive charge is made up of calcium, sodium, potassium and magnesium. This specifies the condition of the body’s acid-base ratio, water balance, endocrine and renal systems. These indicate the condition of your body's acid-base ratio, endocrine and renal systems, water balance and other conditions. There is a fine line between…

    • 830 Words
    • 4 Pages
    Good Essays
  • Satisfactory Essays

    Electrical Conductivity

    • 449 Words
    • 2 Pages

    ELECTRICAL CONDUCTIVITY IN SOLUTION REPORT By: Dwinita Ayuningtyas ( X2 / 10) Elizabeth Irianti ( X2 / 10) M. Ariefur Rohman ( X2 / 10) Richa Wahyu A. ( X2 / 10) Tiara Faradina P. ( X2 / 10) Yanuar Alfa T.S. ( X2 / 10) [pic] Worship and praise we prayed the presence of god almighty who has guided and directed us, so we can resolve this chemical report. We make this report to refine the experiment on the Electrical Conductivity In Solution we’ve done a few days ago…

    • 449 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Chemistry December 14, 2010 Conductivity of Ionic solutions Introduction This lab report is about the conductivity of ionic solutions. In class we have been discussing wether all ionic solutions conduct equally well. If an solvent solution conducts electricity, then it must contain ions. So measuring the conductance of solutions can tell you whether the solutes in the solution are dissociated into ions. (Conductivity) Any type of solution, even ionic solutions, provide resistance to the flow…

    • 949 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    Conductivity

    • 1845 Words
    • 8 Pages

    Name: Basic Coordinates & Seasons – Student Guide There are three main sections to this module: terrestrial coordinates, celestial equatorial coordinates, and understanding how the ecliptic is related to seasons on the Earth. Each of these sections has its own simulator(s). The background material necessary to utilize these tools is contained in each section. Terrestrial Coordinates Work through the explanatory material on units of longitude and latitude, finding longitude and latitude, and…

    • 1845 Words
    • 8 Pages
    Powerful Essays
  • Good Essays

    EXPERIMENT 5 Title: Conductivity of Strong Electrolytes Date: 16 August 2005 Objectives: ▪ To determine the relationship between the concentration and conductivity of various electrolytes ▪ To determine the conductivity at infinite dilution ▪ To determine the activity coefficients Theory: The resistance, R of a conductor with a similar cross section is proportional to the length (l) and inverse to the cross section area(A), therefore; [pic]…

    • 1006 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Thermal Conductivity

    • 752 Words
    • 4 Pages

    good a material is at conducting heat is known as its thermal conductivity. Thermal conductivity is defined as the rate at which heat flows through a certain area of a Object of the experiment is to determine the thermal conductivity of metals and insulation body.materials and also to demonstrate that heat flow is directly proportional to temperature differences between faces and to cross sectional area. Thermal conductivity is defined as:…

    • 752 Words
    • 4 Pages
    Good Essays