Solvay
Process
2NH3 + CO2 + H2O (NH4) 2CO3
A
(NH4) 2CO3 + CO2 + H2O 2NH4HCO3 (aq.)
B
NH4HCO3 + NaCl ->NaHCO3 + NH4Cl
B
NaHCO3 is used in:
•water treatment;
•as an additive in food and drinks – eg baking powder;
•for blowing foams such as expanded polystyrene;
•in pharmaceutical products as an antacid;
•in personal care products such as toothpaste; and
•as an additive in animal feeds.
2NaHCO3  Na2CO3 + CO2 + H2 O
Heavy soda ash
55% Glass containers
20% Chemicals, metallurgical, detergents
25% Flat glass, glass fibre and other glass Heavy soda ash
Light soda ash
40% Heavy chemicals (Phosphates, silicates and chromates)
30% Food, drinks, detergents, textiles and miscellaneous
30% Brine treatment and water purification
The overall reaction:
2NaCl(aq) + CaCO 3 (s) Na 2 CO 3 (aq) + CaCl 2 (aq)
is endothermic (H = +20 kJ mol –1 , G = +60 kJ mol –1 )
and the equilibrium lies well to the left. So the production of sodium
carbonate must
be undertaken by an indirect route. The actual series of reactions used is:
1) CaCO 3 (s) →CaO(s) + CO 2 (g) ∆H = +178 kJ mol –1
2) 2NaCl(aq) + 2NH 3 (aq) + 2H 2 O(l) + 2CO 2 (g) 2NH 4 Cl(aq) +
2NaHCO 3 (s)
∆ H = -158 kJ mol –1
3) 2NaHCO3(s) →Na2CO3(s) + CO2(g) + H2O(l) ∆ H = +85 kJ mol –1
4) CaO(s) + H 2 O(l) →Ca(OH)2 (s)
∆H = -65 kJ mol –1
5) Ca(OH)2 (s) + 2NH 4Cl(aq) →CaCl 2 (aq) + 2NH 3 (aq) + 2H 2 O(l)
∆H = -20 kJ mol –1
Biological CaCO3
Calcitic microlenses as part of the photoreceptor system in brittlestars
Joanna Aizenberg, Alexei Tkachenko, Steve Weiner, Lia Addadi
Nature 412, 819, 2001
Biomineralization on Organic Matrix
c
a
b
Aragonite
Acidic
Macromolecule
Silk-fibroin-like
proteins
β-chitin
Asymmetry of biominerals in life]
Chirality of Calcite Single Crystals in a Coccoltih
The Concept of A Single Crystal in Biomineralization
Pure synthetic calcite crystal
a: intact spine from the sea urchin
b: fracture surface of a young spine
c: fracture surface of a mature spine
埃及豔后與珍珠
Cleopatra
Pearl of Allah
By Aaron Klein
© 2004 WorldNetDaily.com
Osama bin Laden tried to
purchase the world's largest
pearl, the Pearl of Allah, as a
gift to Saddam Hussein "to
unite the Arab cultures," and
Hussein was prepared to
accept………………
$ 40 Million
Germanium Ge
The element is a gray-white metalloid, and in its
pure state is crystalline and brittle.
GeO2 + 2C
GeO2 + 2H2
Ge + 2CO
Ge + 2H2O
Very pure germanium can be made by the reaction of GeCl4 with
hydrogen.
GeCl4 + 2H2
Ge + 4HCl
Germanium was an element whose existence was predicted by
Mendeleev in 1871. He predicted that the then unknown element
germanium should resemble silicon in its properties. He suggested
therefore the name ekasilicon (symbol Es). Germanium was
discovered in a mineral called argyrodite by Clemens Alexander
Winkler in 1886.
•It is stable in air under ambient conditions but on heating in
air or oygen, tin reacts with oxygen to from tin dioxide, SnO2.
Sn(s) + O2(g)
SnO2(s)
It is stable to water under ambient conditions but on heating with steam,
tin reacts with water to from tin dioxide, SnO2 and hydrogen.
Sn(s) + 2H2O(g) SnO2(s) + 2H2(g)
Chlorides
•SnCl2: tin (II) chloride
•SnCl4: tin (IV) chloride
Ionic
Covalent
Alloy : Tin is used to form many useful alloys. Bronze is an alloy of
tin and copper
Lead
General Information
Lead is stable to air and water, but will
tarnish in moist air over long periods. It
dissolves in nitric acid. Lead is a poor
conductor of electricity.
•Lead is a soft, malleable and corrosion resistant
material.
•Lead is used to line tanks that store corrosive liquids,
such as sulfuric acid (H2SO4).
•Lead's high density makes it useful as a shield
against X-ray and gamma-ray radiation and is used in
X-ray machines and nuclear reactors.
•Lead is also used as a covering on some wires and
cables to protect them from corrosion, as a material
to absorb vibrations and sounds and in the
manufacture of ammunition.
•Most of the lead used today is used in the
production on lead-acid storage batteries, such as the
batteries found in automobiles.
Roman baths such as these in Bath,
England, used lead pipes for water
The ancient Romans used lead to make water pipes, some of which are still in use
today. Unfortunately for the ancient Romans, lead is a cumulative poison and the
decline of the Roman empire has been blamed, in part, on lead in the water supply.
鉛 彈!鉛 彈! 我打你的小蛋
蛋!
小子 你剛轉來的?
Lead (II) oxide
In chemistry, the inert pair effect occurs when electrons are pulled
closer to the nucleus, making them stabler and more difficult to ionise.
This is a relativistic effect.
An electron around the nucleus requires sufficient kinetic energy in order
not to be pulled towards the nucleus. This results in it having higher
speeds, with a higher force acting on it by the nucleus. The effects for the
heavier elements are appreciable, as electrons travel closer to the speed
of light, c. The s-orbital electrons are more affected in this way since
they have a greater penetrating power.
The mass of the electron depends on its speed, given by its rest mass
multiplied by the Lorenz factor. Electrons in heavier elements thus have
greater increases in their relativistic masses.
The consequence of this is that the Bohr radius is decrease.
As the electrons are pulled closer to the nucleus by this effect, they are
stabilised and harder to ionise. This is called the inert pair effect.