INORGANIC CHEMISTRY
METALS
PHYSICAL PROPERTIES
1. Solids at room temp except mercury.
2. Have high melting points except the alkali metals.
3. Possess a luster (shiny appearance)
4. Good conductors of heat and electricity
5. Malleable, ductile, have high tensile and
high densities (except alkali metals)
6. Have high densities
7. Sonorous
CHEMICAL PROPERTIES
1. Reacts with oxygen to form basic oxides
2. Reacts with water or steam to form basic oxides/hydroxides. Exceptions are Zn, Al and Pb
which are amphoteric.
3. Metals above hydrogen in the reactivity series reacts with dilute acids to produce a salt and
hydrogen.
4. Reacts with nonmetals to form ionic compounds.
5. Very electropositive metals form ionic hydrides.
6. Electropositive, lose electrons to form ions.
7. Reducing agents.
8. Forms ionic chlorides
REACTION WITH WATER: Metals will react with water or steam to produce the hydroxide and
hydrogen gas.
REACTION WITH OXYGEN: Metals will react with oxygen to produce the oxide.
REACTION WITH DILUTE ACIDS (HCl, H2SO4): Metals will react with dilute acids to produce a
salt and hydrogen gas.
REACTION OF METALLIC OXIDES/HYDROXIDES: These will react with acids to form salt and
water. There is no reaction with metals below hydrogen.
ACTION OF HEAT (THERMAL DECOMPOSITION) ON:
NITRATES: Metals high in the reactivity (Na & K) series will have their nitrates decompose to
give the nitrite and oxygen. The other metals will have their nitrates decompose to give the
oxide, nitrogen dioxide and oxygen.
CARBONATES: Metals high in the series form stable carbonates. Those lower in the series will
have their carbonates decompose to form the oxide and carbon dioxide.
HYDROXIDE: The hydroxides of metals such as Na & K that are high in the series will not be
affected by heat and are stable. Metals lower will be decomposed by heat to give the oxide and
water
REACIVITY SERIES: They is a list of the commonly used metals in order of decreasing reactivity.
The metals at the top are the most electropositive. They react very easily to form positive ions
and are not easily displaced to form atoms. Those at the bottom are least electropositive. They
are not easily ionized and are very stable as atoms.
K
Na
Ca
Mg
Al
Zn
Forms positive ions easily. They are extracted by electrolysis of their molten
compounds. Reacts easily with oxygen forming oxides.
Fe
Found mostly as their oxides, carbonates and sulphides. Extracted by the reduction of
their oxides using carbon or carbon monoxide.
Sn
Pb
(H)
Cu
Found free in nature. Copper is extracted by displacement or by electrolysis of aqueous
Ag
solution.
Au
The metals from potassium to lead cannot be extracted by electrolysis of their solution as
hydrogen gas will be produced at the cathode. The metals from K to Al cannot be extracted by
reduction of their oxides by carbon because the oxides are too stable and would require too
high a temperature that would make it too impractical and uneconomical. They are too reactive
to be displaced from solutions.
Zn and Fe are extracted by the reduction of their oxides using carbon or carbon monoxide as
their oxides are not so stable and require a lower temperature.
EXTRACTION OF IRON
The ores used are haematite (Fe2O3), Magnetite (Fe3O4) and Iron (11) carbonate. The extraction
is carried out in a blast furnace. The ore, coke and limestone are fed at the top as the charge.
Hot air is pumped in at the bottom through pipes. The reduction takes place in stages. In the
lower part of the furnace, stage 1, the coke burns in the air to form carbon dioxide. This is an
exothermic reaction and the temperature can e as high as 20000C.
Eq. 1
As the carbon dioxide moves up the furnace, more carbon (coke) reduces it to carbon
monoxide. This reaction is endothermic, so at stage 2, the temperature has fallen to about
1100oC. Here the supply of oxygen is less.
Eq. 2
At stage 3, the carbon monoxide reduces the iron ore to form molten iron and carbon dioxide.
The temperature at this stage is about 900oC. The limestone used decomposes to calcium oxide
and carbon dioxide. The oxide, which is basic, reacts with the impurity, silica, which is acidic,
forming a salt called calcium silicate. This salt is also called slag. The molten iron is heavier than
the slag and sinks to the bottom. Both are tapped off at the bottom of the furnace.
The hot air exiting at the top is used to heat the incoming air. The cast iron formed is impure as
it has a high percentage of carbon.
EXTRACTION OF ALUMINIUM
The main ore in the extraction of Al is bauxite. Pure alumina has a very high melting point so it
is dissolved in molten cryolite which is another ore of aluminum. The cryolite acts as a solvent
so that the Al ions may be set free. The temperature is lowered to approx. 1000 oC. The
extraction is carried out in an electrolytic cell which is made from steel. The electrodes are
made from graphite. When the electricity is switched on, the positive Al ions will migrate
towards the cathode. Here they are reduced to form molten Al. This is collected at the bottom
of the cell where it is tapped off. The negative oxygen ions are attracted towards the anode
where they are oxidized to oxygen molecules. This will react with the carbon electrode to form
carbon dioxide.
ALLOYS: These are mixtures of metals. Nonmetals can also mix with metals. Alloying metals will
give metals the following properties: a) increase corrosion resistance. b) Decrease the melting
point of the metal. c) Decrease the malleability and ductility while increasing the hardness,
toughness and tensile strength.
PROPERTIES AND USES OF METALS AND THEIR ALLOYS (IEAD, ALUMINUM AND IRON)
CORROSION: This is the reaction of a metal with chemicals in its environment resulting in the
surface of the metal gradually wearing away. Some forms of corrosion are beneficial as the
oxide layer that is formed protects the metal beneath it once it is formed. The layers formed on
Cu and Al protects these metals from further corrosion. When iron and steel corrode, hydrated
iron (III) oxide is formed. This is also called rust. This layer does not protect the metal from
further corrosion and will peel away leaving the metal exposed for further corrosion. Both
moisture and air must be present for rusting to take place.
RUST PREVENTION
1. Anodising. 2. Electroplating.
3. Painting.
4. Alloying.
5 Sacrificial protections.
6. Coating with grease
IMPORTANCE OF METALS TO LIVING SYSTEMS AND ENVIRONMENT
Ca: Bone and teeth formation. Formation of shells. Essential for clotting of blood
Cu: Need for the absorption of iron in the formation of haemoglobin. Assist in the formation of
collagen and melanin.
Fe: Present in haemoglobin and the transport of oxygen. Essential for proper plant growth.
Mg: Essential in the formation of chlorophyll. Needed for functioning of many enzymes in the
human body.
K/Na: Assist in the transmission of nerve impulses
Cr: Essential in the regulation of glucose in the body
Mn: Essential in the formation of enzymes, bones and amino acids
Zn: Present in enzymes. Essential for growth and metabolism and proper functioning of
immune system.
HARMFUL EFFECTS OF METAL
Most metals are poisonous to living organisms if present in sufficient quantity. They can enter
the atmosphere through industrial processes, fossil fuel burning, pesticides, fertilizers etc. They
will remain i in the environment and accumulate up the food chain affecting tertiary
consumers.
METAL: Hg
SOURCE: fossil fuel burning, dental filling and canned tuna, thermometers,
fluorescent lights
EFFECTS: Kidney damage, damage nervous system, muscle tremors, inflammation of mouth and
gum, personality changes.
METAL: Pb
SOURCE: water pipes, cigarettes, solder, batteries, car exhaust, paints
EFFECTS: Mental confusion, antisocial behavior, paralysis, anorexia, vomiting, damage body
tissues and organs, interfere with formation of red blood cells, causes low IQ in children and
permanent learning disorders.
METAL: Cd
SOURCE: coal burning, fertilizers, electroplating, Zn manufacture, batteries
EFFECTS:
Extreme restlessness, chest pains, diarrhea, vomiting
METAL: Cu
SOURCE: water pipes, canned greens, pots, jewelry, meat with CuSO4
EFFECTS:
mental disorder, arthritis, schizophrenia, insomnia, liver enlargement &
inflammation
METAL: As
SOURCE: Mining of gold, burning of fossil fuel, extraction of metals
EFFECTS:
Cancer causing, damages nervous system, heart and blood vessels
NON METALS
GENERAL PHYSICAL PROPERTIES
1. Dull in colour, no luster.
2. Brittle solids, not malleable or ductile
3. Poor conductors of heat and electricity except for graphite
4. Usually gases or solids at r.t.
5. Have low m.p., b.p. and densities.
CHEMICAL PROPERTIES
1. React with metals to form ionic compounds
2. React with oxygen to form acidic oxides except CO
3. Do not react with dilute acids
4. Most are oxidizing agents except C and H. They ionized by gaining electrons or do not form
ions.
5. Do not react with water except Cl.
6. React with themselves or other non-metals forming covalent compounds.
PHYSICAL PROPERTIES OF: hydrogen, chlorine, oxygen, carbon, Sulphur, nitrogen
REACTION OF NON-METALS WITH OXYGEN
LABORATORY PREPARATION AND USES OF:
Ammonia – react ammonium chloride with calcium hydroxide, very soluble in water, less dense
than air, collected by downward displacement of air, CaO as a drying agent
Carbon dioxide – react calcium carbonate with hydrochloric acid, slightly soluble in water,
slightly denser than air, collected by upward displacement of air, can be collected over water
with Con. H2SO4 and anhydrous CaCl2 as drying agents
Oxygen – decomposition of hydrogen peroxide using manganese dioxide, slightly soluble in
water, slightly denser than air, collected by upward displacement of air, can be collected over
water with CaO, anhydrous CaCL2 or Conc. H2SO4 as drying agents
USES OF: carbon, sulphur, phosphorous, chlorine, nitrogen, silicon and their compounds.
NON METAL &
COMPOUNDS
Sulphur and its compounds
Carbon/compounds
Phosphorous
Nitrogen
Chlorine
Silicon
USES
Vulcanize rubber, medicinal drugs, fungicides, matches, H2SO4,
food preservatives, fertilizers
Jewelry, tip of drills, lead in pencils, solid lubricant, electrodes,
bicarbonate in Na2CO3, fire extinguishers, Raising agent
Matches, pesticides, explosives, phosphoric acid, flares, fireworks,
fertilizers
Liquid nitrogen freeze foods, fill light bulbs, packaging, ammonia,
household cleaners, fertilizers, nitric acid explosives
Bleaching agent for water, pesticides, antiseptics, dry-cleaning
fluids, PVC, disinfectants, make bleach
Silicon chips, silicon implants, steel alloys, jewelry, manufacture
glass, cement, concrete, ceramic products
HARMFUL EFFECTS OF NON-METALS ON LIVING SYSTEMS AND ENVIRONMENT:
oxides of nitrogen, CO, CO2, SO2, H2S, CFCs, carbon particles, nitrates, phosphates, pesticides
SULPHUR DIOXIDE-- Acid rain, respiratory problems
CARBON DIOXIDE
Greenhouse effect and global warming, Cause acidification of oceans
CARBON MONOXIDE Easily binds with haemoglobin more than oxygen causing reduction of
oxygen
HYDROGEN SULPHIDE
binds easily with haemoglobin reducing cellular respiration
OXIDES of NITROGEN
Respiratory problems, acid rain, photochemical smog
CFCs (Chlorofluorocarbons) breakdown ozone layer resulting in more UV light reaching earth
NITRATES and PHOSPHATES eutrophication
effects of pesticides Harm useful organisms, concentrate up the food chain
CARBON PARTICLES
blackened trees, combine with water vapour and SO2 to form smog
DISPOSAL of SOLID WASTE
Plastics are non-biodegradable fills landfills, release toxic
chemicals- air pollution, clogged waterways (recycle them)
UNIQUE PROPERTIES OF WATER: maximum density at 4 0C, high specific heat capacity, high
heat of, solvent property -dissolves a large number of substances, Volatility –high heat of
vaporization, high melting/boiling points.
CONSEQUENSES OF SOLVENT PROPERTIES:
1. Water hardness. Hard water: Ca2+ and Mg2+ ions [temporary hardness (contains
hydrogen carbonate ions) and permanent hardness (contains sulphate ions)],
2. Water pollution- water dissolves water soluble pollutants and become polluted.
Pollutants include heavy metals, oxides of Sulphur and nitrogen forming acid rain,
nitrates and phosphates, pesticides, untreated sewage,
3. Leaching – loss of water-soluble nutrients from the soil as water passes through it
TREATMENT OF WATER FOR DOMESTIC PURPOSES: boiling, filtering, chlorination with NaClO,
softening of hard water using sodium carbonate and distillation.
Ca(HCO3)2 + Na2CO3
CaCO3 + 2NaHCO3
removal of temporary hardness
CaSO4 + Na2CO3
CaCO3 + Na2SO4
removal of permanent hardness
GREEN CHEMISTRY: The utilization of a set of principles that reduces or eliminates the use or
generation of hazardous substances in the design manufacture and application of chemical
products and processes.
TWELVE PRINCIPLES OF GREEN CHEMISTRY: prevent waste, maximize atom economy, design
less hazardous chemical syntheses, design safer chemicals and products, use safer solvents and
auxiliaries, increase energy efficiency, use renewable feedstocks, reduce derivatives, use
catalysts, design for degradation, analyse in real time to prevent pollution, minimize the
potential for accidents.
QUALITATIVE ANALYSIS: Identify NH4+, Cu2+, Fe2+, Pb2+, Zn2+, Ca2+, Al3+, Fe3+ by colour and the
solubility of their hydroxide in aqueous sodium hydroxide and ammonium hydroxide solution.
Identify CO32-, SO42-, SO32-, NO3-, Cl-, Br-, I-
IDENTIFY THE FOLLOWING GASES: H2, O2, N2 CO2, NH3, SO2, Cl2 and H2O by colour, odour,
reaction with glowing or burning splint, reaction with moist litmus paper, reaction with dry
cobalt chloride paper/ anhydrous copper sulphate, reaction with acidified potassium
manganate (VII), acidified potassium chromate (VI), reaction with concentrated ammonia or
concentrated hydrochloric acid, hydroxide reaction with lime water/aqueous calcium.
HYDROGEN
Colourless gas
OXYGEN
AMMONIA
colourless
colourless
HYDROGEN CHLORIDE
colourless
NITROGEN DIOXIDE
Dark brown
CARBON DIOXIDE
colourless
CHLORINE
Yellow green colour gas
SULPHUR DIOXIDE
colourless
WATER VAPOUR
colourless
Lighted splint goes out with a
pop
Relights a glowing splint
Red litmus paper changed to
blue, white HCl fumes with
conc, HCl
White fumes of ammonium
chloride with ammonia
Dark brown gas. Turns blue
litmus paper red
White precipitate of calcium
carbonate with calcium
hydroxide. Will become
colourless with excess CO2
Turn blue litmus red then
bleached.
Turn acidified potassium
permanganate colourless,
change acidified potassium
dichromate green from
orange.
Cobalt chloride paper from
blue to pink. Anhydrous
copper sulphate from white to
blue