3.1.11 - Electrode Potentials and Cells Flashcards
Give the definiton of a electrochemical series
Series of chemicals arranged in order of standard electrode potential
What is the general formula for writing a conventional series?
(element being oxidised)|(oxidised)|(oxidised)|(reduced element)
What occurs at the negative electrode?
Loss of electrons (oxidation)
What is the formula for calculating total EMF?
Reduced - oxidised
What is a hydrogen cell used for?
To measure the standard electrode potential of a half cell
What are the standard conditions for measuring electrode potentials?
- 298K, 100 kPa
- 1.00 moldm-3 concentration solutions and [H+]
- H2 gas, Pt electrode
Which element will be oxidised based on EMF?
The one with the more negative EMF
Which element will be the strongest oxidising agent based on EMF?
The one with the highest EMF
Why is a Pt catalyst used?
It conducts electricity and is inert
How is a reaction reversed?
Input of current causes electrons to flow in the opposite direction, reversing the reaction
What is the purpose of the salt bridge?
- Allows ions to move across
- To complete the circuit
What are 2 advantages of using a hydrogen fuel cell?
- Only produces water as waste product
- Wastes less energy compared to a combustion engine
What is the first stage of conducting an electrode potential practical?
- Weigh out moles of compound
- Disolve in acid
- Transfer to volumetric flask and make up to mark
What is the second stage of conducting an electrode potential practical?
- Immerse piece of metal into solution
- Connect half cells via salt bridge
- Connect voltmeter to both cells
What is the last stage of conducting an electrode potential practical?
- Record emf
- Use EMF equation to work out the electrode potential of the relevant element
