Option 1: CH4 + H2O -> CO + 3H2

In this reaction, 1 g of compound is decomposed, and the maximum quantity of H2 gas is produced. Methane (CH4) reacts with water (H2O) to form carbon monoxide (CO) and three moles of hydrogen gas (H2). Since the quantity of H2 gas produced is directly proportional to the number of moles, this reaction produces the maximum quantity of H2 gas compared to the other options.

Option 2: CO + H2O -> CO2 + H2

In this reaction, carbon monoxide (CO) reacts with water (H2O) to form carbon dioxide (CO2) and one mole of hydrogen gas (H2). Only one mole of H2 gas is produced, which is less than the three moles produced in option 1.

Option 3: CH4 + O2 -> CO + 2H2

In this reaction, methane (CH4) reacts with oxygen (O2) to form carbon monoxide (CO) and two moles of hydrogen gas (H2). Although this reaction produces a higher quantity of H2 gas compared to option 2, it is