A sample of hydrogen gas collected at STP occupies 181mL. The gas is heated to 25degree Celsius and is found to occupy 200mL.what is its new pressure in mm Hg?

1 Answer
Apr 22, 2018

#PV = nRT#

Explanation:

#V_(H_2) = 181 * 10^(-6) = 0.000181 m^3#
My definition of #s.t.p# is #100000 Pa# and #273K#. It could be different from your values so caution here.
#PV = nRT#

#(100000)(0.000181) = n(8.31)(273)#

#n = 0.00798 mol#

Since moles do not change, we use this as the new constant and apply #PV = nRT# again in new conditions.

#(P)(0.0002) = (0.00798)(8.31)(298)#

#P = 98800 Pa# or #P = 0.975 atm#