Experiment Plan. Chemistry IA: Electrolysis of Metal Sulphate solutions (NiSO4)
Chemistry IA: Electrolysis of Metal Sulphate solutions (NiSO4)
Introduction
Electrolysis is the chemical decomposition of a compound by applying an electric current through a solution containing ions. Electrolytes are required to conduct electricity. They must be dissolved in water or in molten state for the electrolytes to conduct because then, the ions are free to move allowing the solution to be electrolyzed.[1] In electrolysis, reduction happens at the cathode whilst oxidation happens at the anode. Reduction is the loss of electrons and oxidation is the gain of electrons.
Research Question
In this experiment, I will be electrolyzing nickel sulphate (NiSO4) solution. To further explain the aim of this experiment, I have formulated a research question: “How does changing the current affect the mass of nickel deposited at the cathode in the electrolysis of nickel sulphate?”
Hypothesis
I predict that as the electrical charge increases, the mass of nickel deposited at the cathode after electrolysis will also increase. Faraday’s law of electrolysis, which investigates the quantitative relationship on electrochemical, can support this. Faraday’s law states, “The amount of the substance produced by current at an electrode is directly proportional to the quantity of electricity used”.[2]
During this electrolysis experiment, the aqueous solution of Nickel Sulphate will transfer Nickel from the anode to the cathode. Therefore indicating that the nickel sulphate solution is ionised by the electric current and dissociated into nickel ions and sulphate ions. This can be represented in a chemical equation: NiSO4 Ni2+ + SO42-