By definition electrochemistry is the science that deals with the relation of electricity to chemical changes and with the inter-conversion of chemical and electrical energy (Definition of electrochemistry n.d.). The process of an electrochemical reaction is one which is either caused by the movement of current or a result of the movement of electrical current. This process is commonly known as a redox (oxidation-reduction) reaction (Conjecture Corporation 2014). In this process one atom/molecule gives off its electrons to another atom/molecule. The atoms/molecules reacting are relatively far from each other, this forces the electrons being transferred to move a larger distance thus producing and electrical current (Conjecture Corporation …show more content…
A salt bridge is generally an upside down U-shaped glass tube. This tube creates a pathway for the ions to move ensuring the electrical neutrality of a solution and it also separates the two electrolytes (A.Olivier 2010). A traditional salt bridge would consist of a solution such as KNO3 (aq) whose ions will not react with the electrolyte or the electrodes (Kumar 2005). In this investigation I will not be able to measure the temperature of the electrolytes, the investigation as a whole will take place in room temperature, 25°C.

Investigative question:
What effect does the cell potential have on the voltage and current produced by a galvanic cell?
Aim:
To determine the voltage and the current produced when Zn is put together with different half cells.
Hypothesis:
The Mg(s)/Mg²⁺ (aq)//Zn(s)/Zn²⁺ (aq) has a greater cell potential therefore will produce a greater voltage and current.
Planned measurements
• Intend to …show more content…
Current(amperes)
2. Electrical potential (Eᶿcell)
3. Voltage ( Volts)
• Independent variable:
Different Zn galvanic cells
• Dependant Variable:
Voltage and Current
• Controlled variables:
1. The Zn(s)/Zn²⁺ (aq) half cell
2. The electrolyte used in salt bridge (KNO3)
3. The amount of electrolyte used in each half cell
4. The amount of time the galvanic cell was left to react
5. The electrodes were kept the metal of the solution used
Apparatus
• 2 pairs conducting wires with crocodile clip at both ends
• salt bridge ( can be made with twisted tissue dipped in electrolyte)
• A data logger
• 4X beakers
• Pen
• Paper
• Working tile
• 30ml of copper sulphide
• 30ml of an Iron sulphate
• 30ml of a Lead sulphate
• 30ml of a Mg sulphate
• 30ml of Zn sulphate

Set up apparatus like shown below:

Circuit connected in series to data logger:

Circuit connected in parallel to data