Group 1 elements for chemistry

1. GROUPI ELEMENTS
Hydrogen (1) 1s1
Lithium (3) [He]2s1
Sodium (11) [Ne] 3s1
Potassium (19) [Ar] 4s1
Rubidium (37) [Kr] 5s1
Cesium (55) [Xe] 6s1
Francium (87) [Rn] 7s1

2. ➢ IB Elements: Copper, Silver & Gold
➢ Characteristics of group I elements
• They have single electron in the valence shell (ns1)
• Group A have underlying structure of (n-1)s2(n-1)p6
• Group B has underlying structure of (n-1)d10
• All are strongly metallic giving rise to M+ cations
• Group B metals can lose d electrons to form M2+ & M3+
cations

3. CHARACTERISTICS
• Group IA are the most reactive - the reactivity increases as one
goes down the group
• The free elements are not found in nature
• Cations are chemically stable - are effectively screened by inert
gas shell of electrons, thus have little polarizing effect on anions
• Hydroxides give alkaline solutions, alkalinity increasing with
atomic #

4. CHARACTERISTICS
• Common salts (inorganic & organic) are ionic, usually colourless &
water soluble
• Aq solns of the salts are neutral to strongly basic depending on
the strength of the anion as a Brӧnsted base
• Outstandingproperties of the salts & their solns is due to the
anions rather than the cations e.g. salts when coloured will be
due to the anion

5. CHARACTERISTICS
• Cations hydrate in aqueous media, degree of
solvation decreasing with increasing atomic number
• In crystalline state only Li & Na regularly form
hydrates
• K & NH3
+ are rarely hydrated & when hydrated the
water is usually associated with the anion

6. SODIUM vs POTASSIUMCOMPOUNDS
•K & Na compounds are remarkably similar in their
properties except for differences in mass & degree of
hydration
•Na compounds are more frequently used because of
cost
•Na compounds are usually more reactive than K
compounds on unit to unit basis because of their
lower atomic wts

7. SODIUM vs POTASSIUMCOMPOUNDS
•This difference may be cancelled when there is
hydration
•Subtle differences sometimes favour the use of K
over Na salts
oA given K salt is often more soluble in non-polar
solvents
oK salts are less deliquescent than corresponding Na
salts
oLiving cells discriminate the 2 salts

8. SODIUM vs POTASSIUM COMPOUNDS
•Na compounds are widely used in pharmacy &
medicine
•With the exception of NaCl in electrolyte
replenishers the therapeutic activity of the
compounds is referable to the anionic component of
the salt

9. SODIUM vs POTASSIUM COMPOUNDS
Na is usually the cation of choice for optimizing the
pharmaceutical utility of organic medicaments e.g.
Penicillin sodium, Sodium citrate, Phenobarbitone
sodium, etc.

10. SODIUM vs POTASSIUM COMPOUNDS
Because of the propensity of Na ion to promote the
retention of water in tissues, Na salts are used with
caution in the treatment of cardiac & renal conditions
in which oedema is a problem

11. SODIUM vs POTASSIUM COMPOUNDS
•Some drugs such as hydrochlorothiazide promote
excretion of K ion to the extent requiring auxiliary
intake of K
•K ion has a diuretic effect
•Thiazides also cause the excretion of magnesium ion

12. RUBIDIUM & CESIUM
•The cations of these elements are quite similar in
behaviour to potassium
•They do not find any application in medicine or
pharmacy

13. LITHIUM
•It is a bridge element
•Its behaviour & that of its salts differs markedly from
those of the alkali compounds but closely resembles
those of magnesium
In every typical element family, the 1st member
of the family more closely resembles the 2nd member
of the following family
These diagonally related elements are known as
diagonals or bridge elements

14. LITHIUM
IA IIA IIIA IVA VA VIA VIIA
Li Be B C N O F
Na Mg Al Si P S Cl

15. LITHIUM
•BeF2 is water soluble but poorly ionized while MgF2
& those of the other alkaline earths are sparingly
soluble
•Unlike Mg & alkaline earths, Be acts as the central
ion of complexes in the solid states & in solutions

16. LITHIUM
•Like Al, Be is amphoteric giving rise to alums &
catalyzes Friedel-Craft’s reactions
•At room temp the free Li metal is less reactive with
water
•It burns in air to form the normal oxide rather than
the peroxide

17. LITHIUM
•Li carbonates & phosphates are only slightly water
soluble
•LiCl is soluble in organic solvents
•Li salts are highly hydrated
•In all these properties Li resembles Mg & to some
extent Ca more closely than Na

18. LITHIUM USES
•Li has no normal physiological roles
•LiCl was at one time used as a salt substitute’ the
physiological activity residing in the anion
•This has been discontinued due to the toxic nature of
Li

19. LITHIUM USES
•The Bromide salt has also been used
•Li2CO3 & Li Citrate act as valuable treatments in
hypomania & manic states
•Patients on lithium treatment must be monitored
closely by following blood Li concentrations

20. AMMONIA & AMMONIUM COMPOUNDS
•NH3 coordinates readily with a proton to form NH4
+
ion
•NH4
+ displays many of the properties of the alkali
metal ions
➢Its salts show striking resemblance to K & Rb salts
with which they are commonly isomorphous

21. AMMONIA & AMMONIUM COMPOUNDS
➢This relationship extends to solubilities as evidenced
by the general water solubility of ammonia salts of
organic & inorganic acids though solubilities of salts
such as bitartrate, chloroplatinate & perchlorate are
lower

22. AMMONIA & AMMONIUM COMPOUNDS - DIFFERENCES
• NH4OH – Ammonium hydroxide ( Ammonia solution) is feebly basic
NH3 + H2O NH4
+ + OH-
•Solutions of ammonium salts are acidic rather than basic

23. AMMONIA & AMMONIUM COMPOUNDS - USES
•Ammonium salts commonly used therapeutically are
CO3
2-, Cl- & Br-
•The bromide is a CNS depressant
•The CO3
2- & Cl- are common ingredients in
expectorant preparations
•In aqueous solution form, ammonia is used in
pharmacy as a mild alkalizer

24. GROUP IB ELEMENTS
•These are Copper (Cu 29), Silver (Ag 47) & Gold (Au
79)
•These elements occur in nature in free metallic state
•They are strikingly different from the alkali metals

25. GROUP IB ELEMENTS
❑Many of their compounds are coloured
❑Their hydroxides & many of their salts are
insoluble in water
❑They readily act as central unit of complexes
❑Their soluble salts are toxic

26. COPPER
• Frequently used monovalent compounds are
Copper(I) oxide; Cu2O & Copper(I) chloride; Cu2Cl2
(Cuprous oxide) (Cuprous chloride)
• Important divalent copper compounds are
Copper(II) oxide; CuO & Copper(II) sulfate CuSO4
(Cupric oxide) (Cupric sulfate)

27. COPPER
•Soluble copper salts are toxic
•Copper is an essential element; small quantities
enhance the physiological utilization of iron
•It occurs in the respiratory pigment, haemocyanin; in
many enzymes & is widely distributed in food

28. COPPER - USES
Copper compounds have been used in a variety of
medical applications:
•Copper gluconate, Cupric chloride dihydrate & Cupric
sulfate pentahydrate are officially cited compounds
•64Cu isotope has been employed in mineral
metabolism studies

29. COPPER - USES
•CuSO4 is the basis of Fehling’s & Benedict’s solutions
used in the classical tests for reducing sugars
•Copper compounds also find application as
fungicides & insecticides
•They are particularly effective as algaecides

30. SILVER
•Common salts of monovalent silver are insoluble or
slightly soluble in water with the exception of nitrate
& fluoride
•Many of these salts including the oxide react with &
dissolve in ammonia water (Iodide & sulfide are
exceptions)
•It also forms +2 series of salts

31. SILVER
•It has oligodynamic action e.g. water distilled in
contact with silver remains sterile over long period
of time
•Its compounds such as Silver nitrate are used in
providing local germicidal action because Ag+ ion
precipitates protein & Cl- in the affected tissue

32. SILVER
•Silver sulfadiazine is used topically as a germicide
•It releases silver slowly from in situ precipitates to
give lasting germicidal action

33. SILVER
•Cosmetic problems can occur because of
discolouration due to the photosensitivity of silver
ion
•Preparations containing silver or silver ions were
once used widely as topical antiseptics for example
MILD SILVER PROTEIN

34. SILVER
•Increasing concentration of Ag+ ion brings about
protein precipitation
•TOUGHENED SILVER NITRATE is formed by adding
AgCl (5%) to reduce brittleness using hydrochloric
acid or potassium chloride
•The resultant product is cast or moulded into sticks
or “pencils” that are used as styptics

35. SILVER
• The ready reducibility of Ag+ ion to elemental state
presents various stability & incompatibilityproblems
• Silver compounds are photosensitive & must
therefore be protected by storage in light-resistant
containers
• Soluble salts are toxic
• Their toxicity is however limited due to local
precipitation of adherent layer of silver protein and
AgCl

36. GOLD COMPOUNDS
•Two series of gold compounds exist:
+1 salts (Aurius) e.g. AuCl: Gold(I) chloride or
Aurius chloride
& the +3 salts (Auric) e.g. AuCl3: Gold (III)
chloride or Auric chloride
•Gold readily acts as a center for the formation of
complexes an example of which is Na3[Au(S2O3)2]
Sodium dithiosulfatoaurate (Sodium
dithiosulfatoaurate(-3) or Gold sodium thiosulfate)

37. GOLD COMPOUNDS
•Chemically gold salts are characterized by instability
to heat, light & even very mild reducing agents
•Simple gold(I) salts will undergo autoxidation giving
rise to finely divided metal & the corresponding
gold(III) compound

38. GOLD COMPOUNDS
•The stability of gold ions is improved by
complexation & particularly if a sulfur linkage is
available
•Gold compounds must be handled with utmost care
due to their ease of reduction & therefore if possible
should be dispensed separately

39. GOLD - USES
•Gold compounds are employed in the treatment of
Lupus Erythematosus & rheumatoid arthritis:
•Aurothioglucose & Gold sodium thiomalate are used
These compounds are poorly absorbed given
orally & are therefore administered parenterally
Dimercaprol (BAL) is used as an antidote if the patient
shows signs of gold toxicity

40. GOLD - USES
•Auranofin [(2,3,4,6-tetra-O-acetyl-1-thio-β-d-
glucopyranosato)(triethylphoshine) gold] is available
in a tablet for treatment of rheumatoid arthritis
•The radioisotope 198Au is employed in the treatment
of some malignancies