IB MYP Integrated Sciences e-Assessment : Corrosion and rusting
Exam Style Practice Questions - New Syllabus
Question (2 marks)
The Statue of Liberty changed colour because the copper metal reacted with oxygen in the atmosphere in a process called corrosion. One of the methods used to prevent corrosion is electroplating. Electroplating is a process that involves coating a thin layer of metal on the surface of another metal using an electric current. This process is commonly used in industry to prevent corrosion or to cover a relatively cheap metal with a more expensive metal, such as silver, gold or zinc. You can see many electroplated objects around you, for example: silver-plated tableware, watches and rings.
The animation below shows how a copper coin can be electroplated.
There are several factors that could affect the mass of the electroplated metal on the coin, for example: current, voltage, concentration of solution, temperature, surface area of metal coin in solution and duration of electroplating.
A student wanted to investigate the electroplating process in her school laboratory. She wanted to coat a copper coin with nickel using a 10 g nickel bar as a source. She wanted to test how changing the current will affect the mass of nickel coating the copper coin. Her equipment is shown below:
Formulate a research question for the investigation.
▶️Answer/Explanation
Ans:
“How does varying the electric current applied during the electroplating process affect the mass of nickel deposited onto a copper coin, while keeping other factors (voltage, solution concentration, temperature, surface area, and duration) constant?”