2NH3 + CO2 + H2O (NH4) 2CO3 A

(NH4) 2CO3 + CO2 + H2O 2NH4HCO3 (aq.) B

NH4HCO3 + NaCl ->NaHCO3 + NH4Cl B

Solvay Process

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 miscellaneous30% 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

AragoniteAcidic MacromoleculeSilk-fibroin-like proteinsβ-chitin

Biomineralization on Organic Matrix

cb

a

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

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………………                             

Pearl of Allah

$ 40 Million

GeO2 + 2C      Ge + 2CO

GeO2 + 2H2      Ge + 2H2O

Very pure germanium can be made by the reaction of GeCl4 with hydrog

en.GeCl4 + 2H2      Ge + 4HCl

Germanium GeThe element is a gray-white metalloid, and in its pure state is crystalline and brittle.

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 Ionic

•SnCl4: tin (IV) chloride 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.