To find the molar amount of hydrogen gas (H₂), you need to use its molar mass and the mass of hydrogen gas you have.
Understanding Molar Mass of Hydrogen Gas (H₂)
The video Molar Mass / Molecular Weight of H2: Hydrogen Gas - YouTube explains that the molar mass of H₂ is 2.02 grams per mole. This means that one mole of hydrogen gas weighs 2.02 grams.
Steps to Calculate Molar Amount
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Determine the Mass: First, you need to know the mass of your hydrogen gas sample, usually measured in grams.
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Use the Molar Mass: Divide the mass of the hydrogen gas by the molar mass of H₂ (2.02 g/mol).
- Formula: Moles of H₂ = (Mass of H₂) / (Molar Mass of H₂)
- Moles of H₂ = mass of hydrogen gas (grams) / 2.02 (grams/mole)
Example Calculation
Let's say you have 10.1 grams of hydrogen gas. To calculate the number of moles, you'd do:
Moles of H2 = 10.1 g / 2.02 g/mol = 5 moles (approximately)This means you have approximately 5 moles of hydrogen gas.
Key Takeaways
- The molar mass of H₂ is 2.02 g/mol.
- You divide the mass of your hydrogen gas sample by its molar mass to find the number of moles.
- The unit of molar amount is moles.
Table Summary
| Quantity | Description | Unit |
|---|---|---|
| Molar Mass of H₂ | The mass of one mole of H₂ | g/mol |
| Mass of H₂ | The amount of hydrogen gas you have | grams |
| Molar Amount of H₂ (moles) | The number of moles of hydrogen gas in your sample | moles |
