How would you find the volume of 7 moles of CH4 at standard temperature and pressure?

1 Answer
Nov 13, 2015

The volume of 7 moles of #"CH"_4"# at STP is approximately #"200 L"#.

Explanation:

STP is 273.15 K and 100 kPa.

Use the ideal gas law, #PV=nRT#, where #P# is pressure, #V# is volume, #n# is moles, #R# is the gas constant, and #T# is temperature.

#P="100 kPa"#
#V= ???#
#n="7 mol CH"_4"#
#R="8.3144598 L kPa K"^(−1) "mol"^(−1)"#
#T="273.15 K"#

Equation
#PV=nRT#

Solution
Rearrange the equation to isolate volume and solve.

#V=(nRT)/P#

#V=(7 cancel(mol) * 8.3144598"L" cancel"kPa" cancel"K"^(−1)""cancel"mol"^(−1) * 273.15cancel"K")/(100cancel"kPa")="159 L"="200 L CH"_4"#(rounded to one significant figure)