Which of the following are two advantages of using hydrogen as a fuel?

• A. Hydrogen produces only water when combusted and has a high energy content per unit mass.
• B. Hydrogen is heavier than most fuels and requires no special handling.
• C. Hydrogen is easily stored at room temperature and is naturally abundant in its elemental form.
• D. Hydrogen combustion releases carbon dioxide and is non-flammable.

Answer: (A)

Verified step by step guidance

1. Identify the key properties of hydrogen relevant to its use as a fuel by recalling its chemical behavior and physical characteristics.
2. Recall that when hydrogen combusts, it reacts with oxygen to form water, which means the combustion product is clean and does not produce carbon dioxide. This is an environmental advantage.
3. Consider the energy content of hydrogen per unit mass. Hydrogen has a very high energy density by mass compared to many conventional fuels, which means it can release a large amount of energy for a given weight.
4. Evaluate the incorrect statements: hydrogen is actually lighter than most fuels, it requires special handling due to its low boiling point and flammability, and it is not naturally abundant in its elemental form but mostly found combined in compounds like water.
5. Summarize that the two main advantages of hydrogen as a fuel are that it produces only water upon combustion and has a high energy content per unit mass.