Redox and redox equilibria

Read our general notes on Risk Assessment

Chemical cells are the basis of electric batteries. Chemical cells are a practical application of redox reactions. With the help of chemical cells it is possible to define electrode potentials and then use them to predict the direction and extent of change of redox reactions. So this introduces another way of answering the questions: 'How far?' and 'In which direction?'.

back to A2 Chemistry

Webguides

• Key ideas about cells and electrode potentials

Recently Asked Questions

• I am currently investigating the iodine clock reaction involving hydrogen peroxide. I don't understand how to work out if the overall equation is redox, especially in view to oxidation numbers? I also understand that the overall reaction can be split into 'half-equations' but am not sure how to go about this. 210208
• I'm doing my background chemistry for a redox titration to determine the concentration of copper ions using potassium iodide. I know the ionic equation I need is: 2Cu²⁺(aq) + 4I^-(aq) -> 2CuI(s) + I₂(aq) I'm having problems explaining why this reaction occurs though because my two half-equations are: Cu²⁺(aq) + e^- ->Cu⁺(aq) - E^o = 0.15 V I₂(aq) + 2e^- -> 2I^-(aq) - E^o = 0.54 V The E^o values would normally mean I would reverse the Cu half-cell as it has the more negative E^o value. But to get my overall ionic equation I actually need to reverse the iodine half-cell. So I'm confused why the reaction occurs. Vikki
• I am investigating the rate of reaction between manganate(VII) and oxalate ions. I am using the colorimeter. It takes time to put the solution into a cuvette. How could i make this accurate? Could I start recording the absorbance after 20 s for each solution to make it fair? I was also wondering how I would investigate the autocatalytic effect. I know I would use MnO, but what do I do with it - vary the concentration maybe? 091008

more

Tests

• Redox equilibria (A2)

updated: 21 August 2003