Hydrogen

Name:Hydrogen
Symbol:H
Atomic Number:1
Atomic Weight:1.00794
Boiling Point:-252.87 °C
Melting Point:-259.14 °C
Density: 11.42 g/cm^3
Electronic Configuration:1
Group Number:1
Group Name:(none). While normally shown at the top of the Group 1 elements in the periodic table, the term "alkaline metal" refers only to Group 1 elements from lithium onwards.
Description:Gas at room temperature, colorless , non-metallic.
About it: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. Hydrogen gas was used in lighter-than-air balloons for transport but is far too dangerous because of the fire risk.The lifting agent for the ill fated Hindenberg balloon was hydrogen rather than the safer helium.

Isolation

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 from 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