A gas sitting in a 5L container at 12 degrees celcius at 3atm, how many moles do you have?

3 Answers
Jul 9, 2018

Answer:

A bit over half a mole....

Explanation:

We simply solve the Ideal Gas equation...

#n=(PV)/(RT)#

#=(3*atmxx5.0*L)/(0.0821*(L*atm)/(K*mol)*(12+273.15)*K)#

#=??*mol...#

Answer:

#0.641435498778218\approx 0.641\ \text{moles}#

Explanation:

From ideal gas equation

#PV=nRT#

where:

  • #P# is absolute pressure of gas

  • #V# is volume of gas

  • #n# is number of moles of gas

  • #R=8.314\ \text{J/mole K}# is universal gas constant.

  • #T# is absolute temperature of gas

#n=(PV)/(RT)#

Setting the values

  • #P=3\ "atm"=3 xx 101325\ "Pa"#,

  • #V=5\ "L"=5 xx 10^{-3}\ "m"^3#

  • #R=8.314 \ \text{J/mole K}#

  • #T=12^0 "C"=12+273=285\ "K"#

we get, the number of moles

#n=\frac{3\times 101325\times 5\times 10^{-3} }{8.314\times 285}#

#=0.641435498778218\ \text{moles}#

#\approx 0.641\ \text{moles}#

Jul 10, 2018

Answer:

You have #"0.6 mol"# of gas.

Explanation:

Use the ideal gas law equation:

#PV=nRT#,

where:

#P# is pressure, #V# is volume, #n# is moles, #R# is the gas constant, and #T# is the temperature in Kelvins.

Known

#P="3 atm"#

#V="5 L"#

#R="0.08206 L atm K"^(-1) "mol"^(-1)#

#T="12"^@"C + 273.15"="285 K"#

Unknown

#n#

Solution

Rearrange the equation to isolate moles. Plug in the known values and solve.

#n=(PV)/(RT)#

#n=(3color(red)cancel(color(black)("atm"))xx5color(red)cancel(color(black)("L")))/(0.08206color(red)cancel(color(black)("L")) color(red)cancel(color(black)("atm")) color(red)cancel(color(black)("K"))^(-1) "mol"^(-1)xx285color(red)cancel(color(black)("K")))="0.6 mol"#
(rounded to one significant figure)