What volume does a "5.0-g" sample of hydrogen gas occupy at STP?
The molar volume of a gas at STP = "22.4 L mol"^(-1)
The molar volume of a gas at STP
1 Answer
Explanation:
The problem provides you with the molar volume of a gas at STP
V_"n STP" = "22.4 L mol"^(-1)
So, you know that under STP conditions for pressure and temperature,
You can use the molar volume of a gas at STP as a conversion factor to help you determine the volume a sample of gas will occupy when kept under STP conditions.
In your case, you need to find volume, so rearrange the molar volume of a gas as
"22.4 L"/"1 mole H"_2 -> this takes you from moles of"H"_2 to liters
Now, in order to find the number of moles present in
5.0 color(red)(cancel(color(black)("g"))) * "1 mole H"_2/(2.016color(red)(cancel(color(black)("g")))) = "2.48 moles H"_2
This sample of hydrogen gas will thus occupy
2.48 color(red)(cancel(color(black)("moles H"_2))) * "22.4 L"/(1color(red)(cancel(color(black)("mole H"_2)))) = color(darkgreen)(ul(color(black)("56 L")))
The answer is rounded to two sig figs, the number of sig figs you have for the mass of hydrogen gas.