What mass of zinc would be needed to fill a 250mL bottle with only hydrogen at 24 degrees celcius and 750mmHg

This is for my chem lab and i have no idea what to do. Here's an equation:
Zn + H2SO4 --> H2 + ZnSO4

Also, if you were collecting hydrogen gas in a bottle over water, would hydrogen be the only gas you'd be collecting?

Zn + H2SO4 → H2 + ZnSO4

PV = nRT
n = PV / RT = (750 mmHg) x (0.250 L) / ((62.36367 L mmHg/ K mol) x (24 + 273 K)) = 0.010123 mol H2

(0.010123 mol H2) x (1/1) x (65.3820 g Zn/mol) = 0.662 g Zn

If you were collecting hydrogen gas in a bottle over water, you would be collecting water vapor as well as hydrogen gas. In that case you need to know the vapor pressure of water at the temperature the collection was made at, in order to make the correction to the gas pressure.

Using the calculator at
http://antoine.frostburg.edu/c…
the vapor pressure of water at 24C is 22.377 mmHg. Then:
(0.010123 mol H2) x ((750 - 22.377) / 750) = 0.00982 mol H2

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