 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Trace Elements Laboratory |
 |
|
|
A
Joint Venture of London Health Sciences Centre and St. Joseph's
Health Care London
|
 |
 |
 |
 |
 |
 |
 |
 |
|
Hydrogen
(H)
|
|||||||||||||||||||||||||
|
This
element is not currently measured in this laboratory.
|
|||||||||||||||||||||||||
Hydrogen is the lightest element. It is by far the most abundant element in the universe and makes up about about 90% of the universe by weight. Hydrogen as water (H2O) is absolutely essential to life and it is present in all organic compounds. In the laboratory, small amounts of hydrogen gas may be made by the reaction of calcium hydride with water. CaH2 + 2H2O Ca(OH)2 + 2H2 This is quite efficient in the sense that 50% of the hydrogen produced comes form water. Another very convenient laboratory scale experiment follows Boyle's early synthesis, the reaction of iron filings with dilute sulphuric acid. Fe + H2SO4 FeSO4 + H2 There are many industrial methods for the production of hydrogen and that used will depend upon local factors such as the quantity required and the raw materials to hand. Two processes in use involve heating coke with steam in the water gas shift reaction or hydrocarbons such as methane with steam. CH4 + H2O (1100°C) CO + 3H2 C(coke) + H2O (1000°C) CO + H2 In both these cases, further hydrogen may be made by passing the CO and steam over hot (400°C) iron oxide or cobalt oxide. CO + H2O CO2 + H2
|
|||||||||||||||||||||||||
Revised March 27, 2008