Электрохимия

Water quality - contamination with heavy metals

Principle

Heavy-metal ions may be carried into surface or ground water from mining fields or via the waste water of galvanic or similar production sites. They block the effect of enzymes so that the processes in the metabolism of the organisms that are controlled by these enzymes may ...

Electrolysis of water

In the case of simple electrolysis (for example electrolysis of water) an electrolysis cell consists of two identical electrodes (mostly graphite or platinum), which are immersed in an (electrolyte) solution. In this experiment sodium hydroxide solution is used as an electrolyte ...

Introduction to the electron transfer reaction

Principle

In this experiment students examine the reaction of metals in salt solutions.  Students put iron or iron wool into a copper sulfate solution and solid copper into an iron sulfate solution.  With this experiment students learn that metals can be deposited from a salt ...

Electrolytic deposition and quantity of electricity (Fara-

During an electrolysis reaction, the deposited mass m of a substance is directly proportional to the flow of charge (First Faraday's law). The second Faraday law states that the electrochemical equivalents k (deposited mass per charge unit) behave like the equivalent masses ...

Hydrogen in the redox series: normal hydrogen electrode

Principle

The redox series is one of the most important tools in "electrochemistry". The redox series arrange metals according to their efforts to emit electrons. The redox series generally begins with the base metals (e.g., iron, zinc) and goes to noble metals (e.g., gold, ...

Faraday's laws

Faraday's first law states that the mass of a material separated by electrolysis is proportional to the quantity of electricity which flowed through the solution. The second law states that the electrochemical equivalents are proportional to their equivalent masses (molar ...

Molten-salt electrolysis

The electrolysis of molten sodium chloride to obtain chlorine and sodium, which can be used to produce sodium hydroxide, is an important industrial-scale process. The experiment is a simple demonstration of the important steps in this process. Due to the high melting point ...

Electrolysis

Principle

The characteristic curve of current against voltage of an electrolytic bath containing copper sulphate solution and having copper electrodes is measured. Visible changes in the electrodes and the bath are observed.

Benefits

• Flexible experimenting thanks to wireless data ...

Electrolysis with measureAPP

Electrolysis with SMARTsense

Conductivity of strong and weak electrolytes with Cobra4

Principle

It is possible to differentiate between strong and weak electrolytes by measuring their electrical conductance. Strong electrolytes follow Kohlrausch's law, whereas weak electrolytes are described by Ostwald's dilution law. The examination of the concentration dependence of the ...

Conductivity titration with Cobra4

Principle

The electric conductivity of aqueous electrolyte solutions is determined by the type and number of charge carriers at constant temperature. Characteristic changes in conductivity are connected with changes in the ionic composition of reacting systems. These can be used in the ...

Determination of the activity coefficient by a conductivity

Principle

The equivalent conductivity of strong electrolytes depends on their concentration. The quotient of the equivalent conductivity at a certain concentration and the equivalent conductivity at infinite dilution is called the conductivity coefficient, which is the result of ...

Nernst equation with Cobra4



Principle

The Nernst equation expresses how the electrical potential of an electrode in contact with a solution of ions depends upon the concentrations (more accurately, activities) of those ions. The equation may be experimentally verified using an electrochemical cell formed from ...

Titration curves and buffering capacity with Cobra4

Principle

pH values can be measured with the aid of electrochemical measurements and proton-sensitive electrodes (e.g. glass electrodes). By combining a glass electrode with a reference electrode in one housing, a single-rod glass electrode, which is appropriate for acid-base titrations, ...