# Chem Question

1. Apr 13, 2005

Lets say you want to find the molar volume of a gas ($$H_{2}$$ specifically). So you basically use a $$Mg$$ ribbon and find the volume of the $$H_{2}$$ gas in a test tube with the $$Mg$$ ribbon. The water fizzes and bubbles. I am having trouble finding the volume of $$H_{2}$$ at STP. I used the formula: $$V_{1} = \frac{P_{1}}{T_{1}} \times \frac{T_{2}}{P_{2}}$$. After plugging in experimental values I got 1.234. Does this make sense? What units is this in. To find the molar volume I know that I do the moles of H_2 gas divided by the volume of H_2 gas. Does it make sense to only have 0.0025 moles of H_{2} gas reacted? Because I se a Mg strip that was 1.20 grams.

Any help is appreciated

Thanks

Last edited: Apr 13, 2005
2. Apr 13, 2005

### QuantumMech

Is that the combined gas equation?

$$\frac{p_{1} V_{1}}{T_{1}} = \frac{p_{2} V_{2}}{T_{2}}$$

Molar volume is the gas' volume divided by the moles of gas.