Avogadro's Law Calculator
Solve for volume or moles at constant temperature and pressure using V₁/n₁ = V₂/n₂. Leave one field blank.
Related Calculators
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Combined Gas Law
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Dalton's Law
Volume of Gas
What is Avogadro's Law?
Avogadro's Law, formulated by Amedeo Avogadro in 1811, states that the volume of a gas is directly proportional to the number of moles when temperature and pressure remain constant.
Molar Volume at STP
At Standard Temperature and Pressure (0°C = 273.15 K, 1 atm), one mole of any ideal gas occupies 22.4 liters.
| Moles | Volume at STP |
|---|---|
| 0.5 mol | 11.2 L |
| 1 mol | 22.4 L |
| 2 mol | 44.8 L |
| 5 mol | 112.0 L |
| 10 mol | 224.0 L |
Step-by-Step Example
Given: V₁ = 22.4 L, n₁ = 1.0 mol, n₂ = 3.0 mol. Find V₂.
Applications
- Stoichiometry: Predicting gas volumes in chemical reactions at constant T and P.
- Balloon inflation: Adding more gas (moles) increases volume proportionally.
- STP calculations: Using 22.4 L/mol as a conversion factor at standard conditions.
Frequently Asked Questions
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Avogadro's Law states that equal volumes of all gases at the same temperature and pressure contain the same number of molecules. The formula V₁/n₁ = V₂/n₂ shows that volume is directly proportional to the number of moles when T and P are constant.
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At Standard Temperature and Pressure (STP: 0°C and 1 atm), one mole of any ideal gas occupies exactly 22.4 liters. This is known as the molar volume of an ideal gas at STP.
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Use Avogadro's Law when temperature and pressure are constant and you need to find how volume changes with the amount (moles) of gas, or vice versa.