SS The Steel Story

SS1 Synopsis

An account of the production, properties and uses of steel. Main topics:

• the nature of steel;

• manufacture of steel;

• different steels for different purposes;

• redox and electrochemical cells;

• rusting and its control;

• chemistry of transition metals.

SS2 Learning outcomes

Candidates should be able to:

(a)     show awareness of the range of types, properties and uses of steel

(b)     explain the importance of the composition of a steel in determining its properties

(c)       describe important redox processes occurring during steelmaking (including removal

       of   sulphur and the reactions during the oxygen blow);

(d)             understand that some substances appear coloured because they absorb in specific parts of the visible spectrum;

(e) use colorimetric measurements to determine the concentration of a coloured solution;

(f)       recall the procedure for carrying out a simple redox titration involving

       manganate(VII)   ions and be able to work out the results;

(g)     recall that transition metals are d-block elements forming one or more stable ions

             which  have incompletely filled d orbitals;

(h)             describe the typical properties of transition metals, exemplified by the first row of the d block with particular reference to iron and copper, including:

(i)         the existence of more than one oxidation state for each element in

its  compounds,

(ii)                 the formation of coloured ions in solution,

(iii)               reactions with ligands to form complexes and reactions involving

ligand  substitution,

(iv)                the catalytic behaviour of the elements and their compounds;

(i)             describe the reactions of Fe²⁺(aq), Fe³⁺(aq) and Cu²⁺(aq) ions with sodium hydroxide  solution and ammonia solution;

(j)    explain the variable oxidation states of transition metals in terms of electronic energy levels;

(k)     explain the catalytic activity of transition metals and their compounds in terms of variable oxidation states;

(l)       explain and use the terms: ligand, complex/complex ion, ligand exchange;

(m)             describe the formation of complexes in terms of bonding between ligand and central metal ion;

(n) explain the term polydentate as applied to ligands, exemplified by edta^4-;

(o)        discuss the shapes of complexes with coordination numbers 4 and 6;

(p)        relate ligand exchange reactions of complexes to stability constants;

(q)             describe redox reactions of d-block elements in terms of electron transfer by:

(i)             using half-equations to represent the oxidation and reduction reactions,

(ii)             combining half-equations to give the overal equation for the reaction;

(r)             describe the construction of simple electrochemical cells involving:

(i)             metal ion/metal half-cells,

(ii)             half-cells based on different oxidation states of the same element in aqueous solution;

(s)        explain and use the term: standard electrode potential;

(t)             describe and explain how a standard electrode potential is measured

(u)        explain the action of an electrochemical cell in terms of half-equations and external electron flow;

(v)         use standard electrode potentials to calculate Ecell  

(w)        use standard electrode potentials to predict the feasibility of redox reactions;

(x)        use standard electrode potentials to predict the relative stability of oxidation states;

(y)        describe rusting in terms of electrochemical processes involving iron and oxygen, and the subsequent reactions to form rust;

(z)             describe and explain:

(i)             approaches to corrosion prevention;

(ii)             issues involved in the recycling of iron.