How can oxidation and reduction be considered?
Oxidation and reduction can be considered in terms of oxygen gain/hydrogen loss, electron transfer or change in oxidation number.
What happens to an oxidizing agent and a reducing agent?
An oxidizing agent is reduced and a reducing agent is oxidized
Do variable oxidation numbers exist for transition metals and most main-group non-metals?
Yes, variable oxidation numbers exist for transition metals and most main-group non-metals.
What does the activity series rank metals based on?
The activity series ranks metals according to the ease with which they undergo oxidation.
What can the Winkler Method be used for?
The Winkler Method can be used to measure biochemical oxygen demand (BOD), which is used as a measure of the degree of pollution in a water sample.
What type of energy is converted into electrical energy in voltaic cells?
Spontaneous, exothermic chemical processes are converted into electrical energy in voltaic cells.
Where does oxidation occur in a voltaic cell?
Oxidation occurs at the anode (negative electrode) in a voltaic cell.
What type of energy is converted into chemical energy in electrolytic cells?
Electrical energy is converted into chemical energy in electrolytic cells.
Where does reduction occur in an electrolytic cell?
Reduction occurs at the cathode (negative electrode) in an electrolytic cell.
What is electromotive force (EMF)?
Electromotive force (EMF) is the energy that drives the movement of electrons from the anode to the cathode in a voltaic cell.
What is the standard hydrogen electrode (SHE)?
The standard hydrogen electrode (SHE) is a reference electrode consisting of an inert platinum electrode in contact with 1 mol dm-3 hydrogen ion and hydrogen gas at 100 kPa and 298 K.
What is standard electrode potential (Eº)?
Standard electrode potential (Eº) is the potential (voltage) of the reduction half-equation under standard conditions measured relative to the SHE.
What happens when aqueous solutions are electrolysed?
When aqueous solutions are electrolysed, water can be oxidized to oxygen at the anode and reduced to hydrogen at the cathode.
What is the relationship between Eº and ΔGº?
The relationship between Eº and ΔGº is given by the equation ΔGº = -nFEº. When Eº is positive, ΔGº is negative indicative of a spontaneous process. When Eº is negative, ΔGº is positive indicative of a non-spontaneous process. When Eº is 0, then ΔGº is 0.
What factors affect the amount of product formed during electrolysis?
The amount of product formed during electrolysis is affected by the current, duration of electrolysis, and charge on the ion.
What is electroplating?
Electroplating is the process of coating an object with a metallic thin layer through electrolysis.