Suppose that 7.47 x 10^-3mol of hydrogen gas occupies a 335 mL container at -91°C what is the pressure (in torr)? i know the answer is 253 .. but idk how to work it? someone please help me?
1 Answer
Use the ideal gas law equation to find the pressure of the sample.
Explanation:
You know that your sample of hydrogen occupies a volume of
Since you know number of moles, volume, and temperature, you can use the ideal gas law equation to determine the pressure of the sample.
#PV = nRT" "# , where
So, rearrange the ideal gas law equation to solve for
#P = (nRT)/V#
Plug in your values and find
#P = (7.47 * 10^(-3)color(red)(cancel(color(black)("moles"))) * 0.082("atm" * color(red)(cancel(color(black)("L"))))/(color(red)(cancel(color(black)("mol"))) * color(red)(cancel(color(black)("K")))) * (273.15 - 91)color(red)(cancel(color(black)("K"))))/(335 * 10^(-3)color(red)(cancel(color(black)("L"))))#
#P = "0.33306 atm"#
To get the pressure in torr, you need to use the conversion factor
#"1 atm " = " 760 torr"#
This will get you
#0.33306color(red)(cancel(color(black)("atm"))) * "760 torr"/(1color(red)(cancel(color(black)("atm")))) = color(green)("253 torr")#
Here are some cool videos to help you get comfortable with the ideal gas law equation