Hydrogen gas is widely studied as a clean alternative fuel. Which industrial chemical process is the most sustainable in terms of the atom economy of the hydrogen produced?
Use the following relative atomic masses: H=1.0H = 1.0H=1.0, C=12.0C = 12.0C=12.0, O=16.0O = 16.0O=16.0.
CH4+H2O→CO+3H2\text{CH}_4 + \text{H}_2\text{O} \rightarrow \text{CO} + 3\text{H}_2CH4+H2O→CO+3H2
CH4→C+2H2\text{CH}_4 \rightarrow \text{C} + 2\text{H}_2CH4→C+2H2
C+H2O→CO+H2\text{C} + \text{H}_2\text{O} \rightarrow \text{CO} + \text{H}_2C+H2O→CO+H2
CO+H2O→CO2+H2\text{CO} + \text{H}_2\text{O} \rightarrow \text{CO}_2 + \text{H}_2CO+H2O→CO2+H2
