1.2 Metals and metal compounds
Metals and metal compounds are found in many different forms in the nature and man-made chemicals. It is important to distinguish between the pure element vs. the ionic form of a metal found in solid and/or solution state. Listed below are some commonly found forms of metals and their compounds. Brief description is also provided to characterize their differences.
A. Earth’s Crust – major ores-
native ores: Au, Ag, Pt, Cu
oxide ores: iron, aluminum, manganese, tin
sulfide ores: zinc, cadmium, mercury, copper, lead, nickel, cobalt, silver
carbonate ores: iron, lead, zinc, copper, calcium, barium, magnesium, strontium
halides: sodium, potassium, magnesium, calcium, silver
sulfates: calcium, strontium, barium, lead
silicates: beryllium, zinc, nickel
phosphates: calcium
B. Oceans
A ton of sea water contains about 55 lbs sodium chloride, 2.5 lbs of magnesium, 1.75 lbs of sulfur, 0.8 lbs calcium, 0.75 lbs potassium, 0.13 lbs bromine and smaller quantities of boron, fluorine and iodine and the metals, strontium, copper, iron, lead, zinc, uranium, silver, gold and even radon.
C. Human Blood
contains 85.2 mM of Na, 44.5 mM of K, 8.59 mM of iron, 2.42 mM of calcium, 1.57 mM of magnesium, 138.4 μM of zinc, 14.8 μM of copper, 2.18 μM of manganese and 0.71 μM of cobalt.
D. Municipal Water
Na+, Ca2+, Mg2+, Fe3+ and Mn2+ are found along with bicarbonate, chloride, sulfate and silicate anions mainly. On evaporation or boiling, calcium sulfate, carbonate and silicate form clogging scales with low thermal conductivity in boilers. Hard water contains excessive amount of Ca2+ and Mg2+ and these metal ions form insoluble salts with soap and detergent.
E. Pure Metals and Alloys – in consumer goods and elsewhere
bronze: 70-95% Cu, 1-25% Zn, 1-18% Sn
solder: 67% Pb, 33% Sn
battery plate: 94% Pb, 6% Sb
dentist amalgam: 50% Hg, 35% Ag, 13% Sn, 1.5% Cu, 0.5% Zn
sterling silver: 92.5% Ag, 7.5% Cu
18 carat yellow gold: 75% Au, 12.5% Ag, 12.5% Cu
18 carat white gold: 75% Au, 3.5% Cu, 16.5% Ni, 5% Zn
yellow brass: 67% Cu, 33% Zn
steels: manganese alloy steel: Fe + 10-18% Mn (railroad rails)
silicon alloy steel: Fe + 1-5% Si (magnets)
alnico: Fe + Al, Ni, Co (permanent magnets)
chrom-vanadium alloy steel: Fe + 1-10% Cr + 0.15% V (axles)
stainless steel: Fe + 14-18% Cr + 7-9% Ni (cutlery, instruments)
high-speed steels: Fe + 14-20% W or 6-12% Mo (high-speed cutting tools)
nickel alloy steel: Fe + 2-4% Ni (drive shafts, gears, cables)
mild carbon steels: Fe + up to ~0.2% C (sheet iron, wire & pipes)
medium carbon steels: Fe + 0.2-0.6% C (rails, structural steel, boiler plate)
high carbon steels: Fe + 0.6 to 1.5% C (surgical instr., razor blades, springs, cutlery)
monel metal: Ni + Cu + a little Fe – highly resistive to oxidation
nichrome and chromel: alloys containing Ni, Fe and Cr – are resistant to oxidation at high temps and show high electric resistance (elec. heating wires, stoves, toasters, irons)
bullets and bearings: Pb hardened with 10-20%