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How many moles of H2 are present in 0.224 L of hydrogen gas measured at STP (273 K and 1 atm)?

1. 0.1
2. 0.01
3. 0.001
4. 1

Correct answer: 0.01

Solution

At standard temperature and pressure (STP), one mole of any gas occupies 22.4 liters. Therefore, to find the number of moles in 0.224 liters, you divide 0.224 L by 22.4 L/mol, resulting in 0.01 moles of H2.

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