IB Chemistry Topic 9 Redox processes Topic 19.1 Electrochemical cells HL

IB Chemistry Topic 9 Redox processes Topic 19.1 Electrochemical cells HL
Predicting the products in electrochemistry and the voltage values. Stoichiometry and electrochemistry calculations.

Full set of resources for topic 9:

0:09 Definitions
0:20 The Standard Hydrogen Electrode (SHE)
1:13 Measuring Standard Electrode values
1:38 The electrochemical series
3:14 Predicting electrode potential values
4:08 Gibbs and electrode potential
5:09 Predicting the products of electrolysis
11:26 Factors affecting electrolysis output
12:54 Electroplating
14:10 Quantitative electrolysis

19.1 Electrochemical cells HL
• A voltaic cell generates an electromotive force (EMF) resulting in the movement of electrons from the anode (negative electrode) to the cathode (positive electrode) via the external circuit. The EMF is termed the cell potential (Eº).
• The standard hydrogen electrode (SHE) consists of an inert platinum electrode in contact with 1 mol dm-3 hydrogen ion and hydrogen gas at 100 kPa and 298 K. The standard electrode potential (Eº) is the potential (voltage) of the reduction half-equation under standard conditions measured relative to the SHE. Solute concentration is 1 mol dm-3 or 100 kPa for gases. Eº of the SHE is 0 V.
• When aqueous solutions are electrolysed, water can be oxidized to oxygen at the anode and reduced to hydrogen at the cathode.
• ∆G° = -nFEº. When Eº is positive, ∆Gº is negative indicative of a spontaneous process. When Eº is negative, ∆Gº is positive indicative of a non-spontaneous process. When Eº is 0, then ∆Gº is 0.
• Current, duration of electrolysis and charge on the ion affect the amount of product formed at the electrodes during electrolysis.
• Electroplating involves the electrolytic coating of an object with a metallic thin layer.
• Calculation of cell potentials using standard electrode potentials.
• Prediction of whether a reaction is spontaneous or not using Eº values.
• Determination of standard free-energy changes (∆Gº) using standard electrode potentials.
• Explanation of the products formed during the electrolysis of aqueous solutions.
• Perform lab experiments that could include single replacement reactions in aqueous solutions.
• Determination of the relative amounts of products formed during electrolytic processes.
• Explanation of the process of electroplating.

Connect with me:

[meghnachaudhury]

Sorry to bother you, but for the electrolysis of water, ( 1/2 O2 +2H+ +2e- ---> H20, ) isn't the forward reaction favoured because it's +1.23? why did you reverse it?

[soumyasharma]

Also, 15:57, [96500/1]=[17550/x] gives us, x=0.181865285= Approx. 0.182 (3SF)