Question #f9fe7

1 Answer
Jun 13, 2017

#2# #"mol"#

Explanation:

To solve this equation, we can use the ideal-gas equation:

#PV = nRT#

where

  • #P# is the pressure exerted by the gas (in #"atm"#),

  • #V# is the volume occupied by the gas (in #"L"#),

  • #n# is the quantity of the gas present (in #"mol"#),

  • #R# is the universal gas constant, equal to #0.082057("L"·"atm")/("mol"·"K")#, and

  • #T# is the absolute temperature of the system (in #"K"#).

Since we want to find the number of #sfcolor(red)("moles"#, let's rearrange the equation to solve for #color(red)(n#:

#n = (PV)/(RT)#

Since all our values are in the appropriate units, we can simply plug them into the equation:

#color(red)(n) = (PV)/(RT) = ((2cancel("atm"))(22.4cancel("L")))/((0.082057(cancel("L")·cancel("atm"))/("mol"·cancel("K")))(273cancel("K"))) = color(red)(2# #color(red)("mol"#

rounded to #1# significant figure, the amount given in the problem.