Metals

Self-evaluation quiz

Question 1.

Select the incorrect statement from the following:

a) damaged Sheffield plate may be repaired by electroplating;

b) moisture and oxygen enhance corrosion;

c) a protective oxide layer forms on the surface of copper objects;

d) microcrystalline wax gives good corrosion protection for iron objects.

Question 2.

Gloves should be worn when handling metal objects so that:

a) oils, fats and sweat are not transferred to the object;

b) the object is less likely to slip from your grip;

c) protective lacquers are not damaged by nails;

d) your hands are not affected by toxic corrosion inhibitors.

Question 3.

Silver cleaning should be carried out only when absolutely necessary because:

a) silver dip solutions are very expensive;

b) any cleaning solutions remove small amounts of silver;

c) cleaning solutions tend to accumulate in indentations and surface cracks;

d) evidence of historic usage may be lost.

Question 4.

Select the correct statement from the following:

a) copper is more susceptible to bronze disease than is brass;

b) bronze disease only occurs in objects recovered from the sea;

c) bronze disease can be treated with a citric acid/thiourea solution;

d) the presence of high concentrations of chloride ions leads to bronze disease.

Question 5.

The presence of brown droplets of moisture on an iron object indicates:

a) there are low levels of chloride ions in the metal;

b) the metal is being attacked by sulphide pollutants;

c) the metal has been buried in a low-oxygen environment;

d) corrosion reactions are still active.

Question 6.

Select the correct statement from the following:

a) wooden cabinets are preferred to painted metal ones for storing metal objects;

b) metal objects should be wrapped in unbuffered, acid-free tissue paper;

c) storage in plastic bags is acceptable as long as they are not made of PVC;

d) relative humidities greater than 45% are essential to help in the release of chlorides from metals.

Question 7.

Which of the following statements are correct?

a) The main corrosion products that form on lead are stable and protective.

b) Abrasives are recommended for the removal of most corrosion products from lead.

c) Use of ethylenediamine tetraacetic acid is effective in removing thin layers of corrosion products.

d) Microcrystalline wax may be applied to lead as a surface finish.

e) Storage of lead in chipboard cupboards is recommended because the resultant lead acetate patina is protective.

Question 8.

Which of the following statements is incorrect?

a) Aluminium may be cleaned with methylated spirits.

b) Caustic soda should be used to remove grease from aluminium.

c) Abrasives should be avoided for cleaning aluminium because they can damage the protective layer.

d) Chloride ions are potentially damaging to aluminium objects.

Question 9.

Citric acid may be used to treat:

a) cast iron, cast steel, spring steel and plated iron;

b) brass and bronze, but only if thiourea is added;

c) silver plate;

d) lead and pewter.