Answer
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Work Step by Step
The data provided supports the idea that oxygen gas is a diatomic molecule because the reaction of 2.0 L of hydrogen gas with 1.0 L of oxygen gas yields 2.0 L of water vapor. The balanced equation for the combustion of hydrogen and oxygen is 2H2 + O2 -> 2H2O.
The balanced equation shows that the 2L of hydrogen gas and the 1L of oxygen gas combine in a 2:1 ratio to form 2L of water vapor, which is consistent with the data provided.
We do not need to consider hydrogen to be a diatomic molecule to explain these results. The balanced equation shows that hydrogen is reacting in a ratio of 2:1, which means it doesn't matter whether hydrogen is diatomic or not. Even if hydrogen is monatomic, we know that 2 moles of hydrogen gas will react with 1 mole of oxygen gas to form 2 moles of water vapor. The fact that hydrogen is diatomic is not needed to explain the data provided.
