Question
How would you prepare dihydrogen from water using a reducing agent?
Solution
1. By the action of water on metals:
(i) Active metals like N,a, K, Ca etc. decompose water at room temperature to liberate hydrogen gas.
(ii) Less active metals like Mg, Al or Zn decompose boiling water producing dihydrogen gas.
(iii) Still less active metals like iron, tin or nickel decompose steam at high temperature.
2. By passing steam over red-hot coke:
When steam is passed over red-hot coke (carbon) at 1270 K, a mixture of carbon monoxide and dihydrogen called water gas is produced.
Dihydrogen is then recovered from water gas either by liquefaction or by Bosch process.
(i) Active metals like N,a, K, Ca etc. decompose water at room temperature to liberate hydrogen gas.
(ii) Less active metals like Mg, Al or Zn decompose boiling water producing dihydrogen gas.
(iii) Still less active metals like iron, tin or nickel decompose steam at high temperature.
2. By passing steam over red-hot coke:
When steam is passed over red-hot coke (carbon) at 1270 K, a mixture of carbon monoxide and dihydrogen called water gas is produced.
Dihydrogen is then recovered from water gas either by liquefaction or by Bosch process.
