D. A type of oxidation (and corrosion), since the iron metal is losing electrons and combining with oxygen
10.
Corrosion, the gradual destruction or degradation of metals due to their reaction with substances such as oxygen, moisture, and acids present in their environment, is best understood as a process driven fundamentally by:
Rancidity, the development of an unpleasant smell and taste in foods containing fats and oils when exposed to air for an extended period, is caused primarily by which type of chemical process?
A.
An amphoteric reaction involving the food's protein content
B.
A neutralisation reaction between the food's natural acids and any added preservatives
C.
Aerial oxidation of the fats and oils present in the food
D.
A precipitation reaction occurring within the food's fat content
C. Aerial oxidation of the fats and oils present in the food
12.
Aluminium metal, despite being a fairly reactive metal, shows good long-term resistance to further corrosion in everyday use (such as in aluminium foil for food packaging) primarily because:
A.
Aluminium does not react with oxygen under any circumstances whatsoever
B.
Aluminium foil is always coated with an artificial plastic layer to prevent any contact with air
C.
Aluminium is, in fact, chemically and physically identical to a noble gas
D.
It rapidly forms a thin, protective layer of aluminium oxide (Al₂O₃) on its surface, which effectively prevents further oxidation of the underlying metal
D. It rapidly forms a thin, protective layer of aluminium oxide (Al₂O₃) on its surface, which effectively prevents further oxidation of the underlying metal
