When a substance goes from being a liquid to a gas it evaporates, or boils away. Think of boiled eggs.
At the same temperature, steam burns are often more severe that water burns because of water's high HEAT OF VAPORIZATION.
Water possesses high heat of vaporization. The heat of vaporization refers to the amount of heat that is needed to convert a unit mass of water to gas. After getting to the boiling point, a lot of heat is still needed to be absorbed by a boiling water before it can be converted to the gaseous form. Thus, the heat that is inherent in the steam is greater than that which is found in the boiling water, that is why the steam causes more damages.
Answer: Moles of hydrogen required are 4.57 moles to make 146.6 grams of methane,
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Explanation:
Given: Mass of methane = 146.6 g
As moles is the mass of a substance divided by its molar mass. So, moles of methane (molar mass = 16.04 g/mol) are calculated as follows.

The given reaction equation is as follows.

This shows that 2 moles of hydrogen gives 1 mole of methane. Hence, moles of hydrogen required to form 9.14 moles of methane is as follows.

Thus, we can conclude that moles of hydrogen required are 4.57 moles to make 146.6 grams of methane,
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