Friday, February 29, 2008

Molten Electrolytes vs Aqueous Electrolytes

Electrolysis is all abt breaking down of an electrolyte into its constituent elements.The products discharged at electrodes depends on da type of electrolyte used in da process, molten or an aq. electrolyte.
if it is a molten one dan its easy to knw da products dat wl b formed. metal ion wl becom a metal nd da non-metal ion to anon-metal...

Electrolysis

Electrolysis is an important O/L chem topic based on its weightage and time spent to teach the topic. On the other hand many students find difficult to answer electrolysis questions. Basic chemistry is essential prerequisite to understand the concepts. For example chemical formula,symbols, state symbols etc.

Learning objectives under dis topic includes:

(a) *describe electrolysis as the conduction of electricity by an ionic compound (an
electrolyte), when molten or dissolved in water, leading to the decomposition of the
electrolyte
(b) *describe electrolysis as evidence for the existence of ions which are held in a lattice
when solid but which are free to move when molten or in solution
(c) describe, in terms of the mobility of ions present and the electrode products, the
electrolysis of molten lead bromide, using inert electrodes
(d) predict the likely products of the electrolysis of a molten binary compound
(e) apply the idea of selective discharge (linked to the reactivity series for cations, see
9.2) to deduce the electrolysis of concentrated aqueous sodium chloride, aqueous
copper(II) sulphate and dilute sulphuric acid using inert electrodes
(f) predict the likely products of the electrolysis of an aqueous electrolyte, given relevant
information
(g) construct ionic equations for the reactions occurring at the electrodes during the
electrolysis of the substances mentioned in the syllabus