COINAGE METALSDr. Althea Rodriguez Arenajo

Copper, Silver and Gold are the members of this family

The group was named because they have been employed for ornamental

and coinage purposes They are closely related with nickel,

palladium and platinum The following are the properties of the

metals:

COINAGE METALS

1. Occur free in nature and are easily recovered from their compounds

2. Are low in the electromotive series, not very active chemically, displaced by most metals

3. Oxides and hydroxides are feebly basic (except Ag2O)

4. The halides are nearly insoluble in water (except Ag)

COINAGE METALS

5. Copper and Gold have 2 series, Silver has 1

6. All of them form complex ions7. Copper is slowly oxidized in air, but rapidly when finely divided and heated in oxygen

COINAGE METALS

Copper was probably the first metal used by man in fashioning various domestic implements and weapons

Cuprite(Cu2O), a red copper ore occurs abundantly and the most impt ore

The feathers of certain birds contain pigments made of copper

Copper is malleable and ductile having a red color by reflected light and greenish color by transmitted light

COPPER

Copper is an excellent conductor of heat (surpassed only by silver and gold) and electricity (surpassed only by gold)

The two copper oxides are red cuprous and black cupric

All copper compounds are insoluble in water

Produce a blue ppt with NH3 water

COPPER

Cupric salts added with K4Fe(CN)6 gives reddish brown ppt

Cupric ions with H2S turns black

Pharmacologic Action of copper ion: Copper and iron metabolism are

interrelated, it has importance in homopoies

COPPER

Hepatolenticular degeneration (Wilson’s disease) results from inability to regulate copper balance

The consequence is that toxic amounts of copper are deposited in various tissues (liver, lungs)

The disease may be treated with chelating agents such as Dimercaprol and edelates

COPPER

Internally, copper is a potential aid to iron assimilation and as emesis

After absorption, Cu is found as copper nucleinate in the liver, blood and bile

Externally, Cu acts as astringent when applied to mucous membrane and abraded surfaces

An effective fungicide (1:1,000,000)

COPPER

Has value in water treatment to remove algae and also of fungus that afflicts humans

A copper compound in tetralin (Cuprex) is used in pediculosis of the head, body or clothing

Copper is not an effective bactericide, only mild antiseptic

Its action is only bacteriostatic

COPPER

Important Compounds:1. Cupric Sulfate NF- Bluestone, Blue

Vitriol Stimulates the vomiting reflex before

there is time for any local irritant action

It is not absorbed, except by corroded stomach therefore, do not produce systemic effects

COPPER

Bordeaux Mixture( copper in combination with lime) is used as fungicide

Used to purify drinking water and swimming pools

In combination with iron or vitamins, has hematinic property

Used externally for its fungicidal action in 1 -5 sol’n

COPPER

Ag is used in making articles of value like coins, ornaments, jewelry

The name Silver was derived from Greek which means “shining”

The Alchemist named it “Luna”, characetrized by crescent moon

The name Luna has survived in Lunar caustic, silver nitrate

Pure silver is a white metal having a metallic luster

SILVER

The most ductile and malleable of all metals, except gold

The best conductor of electricity Silver cyanide complex is added to silver

sol’n for electroplating Silver salts gives a white curdy ppt of AgCl

when treated with HCl Ammoniacal sol’n of silver salts with

formaldehyde and warmed, formed ‘silver mirror’ on the walls of container

SILVER

Important Compouds:1. Silver Nitrate (Argentii Nitras) It is used routinely in the form of 1%

sol’n for instillation in the eyes of newborn babies for gonorrheal infection which is still a legal requirement in some states

(against Ophthalmia neotorium) Dose: 1 drop in each eye

SILVER

Silver Nitrate pencil (Toughened Silver Nitrate) – used for removing warts and other skin excresences and for canker sore in the mouth

A dose of 0.5% is used to treat severe 1st degree burns with 80%

recovery2. Mild Silver Protein ( Mild Protargin) It is used as local antibacterial in aqueous

sol’n at conc from 5-25%

SILVER

It is used as mild antiseptic in the eye, ear, nose and throat

3. Colloidl Silver Chloride (Lunosol)Use: prophylaxis against and treatment

of infections of the accessible mucous membrane such as genitourinary tract and the eye

4. Silver Picrate (Picragol, Picrotol, Silver trinitrophenlate)

SILVER

Use: in the treatment of vaginitis resulting from Trichomonas vaginales and Monilia albicans

5. Strong Silver Protein (Protargol, Argentum Proteinicum Forte, Strong Protargin )

A potent germicide used in conc of 0.25 to 0.5% for irrigation of the bladder and urethra

SILVER

Recognized as the King of all metals since the earliest times because of its

color, scarcity and permanency in contact with the atmosphere

Valued from the earliest ages for making jewelry, coin and etc.

The symbol Au was taken from the Greek aurum, a universal symbol of highest purity and value

GOLD

Gold is one of the most inactive and permanent of all metals

Aqua Regia, best reagent for dissolving gold, can also be dissolve by chlorine and bromine water

Reacts with NaOH and gives a brown ppt of auric hydroxide

Forms soluble salts with acid/base, has amphoteric property

GOLD

Other amphoteric substances are: aluminum, tin, zinc, and lead

Gold when treatd with stannous chloride sol’n slowly forms purple ppt known as purple of Cassius

Modern gold therapy started with the discovery by Koch in 1890, that gold cyanide was effective in vitro against tubercle bacillus.

GOLD

1. Gold Sodium Thiosulfate NF Use: treatment of nondisseminated

lupus erythromatosus, and rheumatoid arhritis

Dose: 5 – 25 mg, intramuscularly2. Aurothioglycanilide3. Aurothioglucose 4. Au Na Thiomalate – (Myochrysine) antirheumatic, rheumatoid arthritis

GOLD