# How many moles of #CO_2# (g) are in a 5.6 L sample of #CO_2# measured at STP?

##### 1 Answer

#### Explanation:

Using the ideal gas equation, we can solve for the number of moles:

#PV=nRT#

where:

Recall that at STP conditions:

#P=101.325# #kPa#

#T=273.15# #K#

To solve for the number of moles of carbon dioxide gas, substitute your known values into the ideal gas equation:

#PV=nRT#

#n=(PV)/(RT)#

#n=((101.325kPa)(5.6L))/((8.314(kPa*L)/(mol*K))(273.15K))#

#n=((101.325color(red)cancelcolor(black)(kPa))(5.6color(orange)cancelcolor(black)(L)))/((8.314(color(red)cancelcolor(black)(kPa)*color(orange)cancelcolor(black)(L))/(mol*color(green)cancelcolor(black)(K)))(273.15color(green)cancelcolor(black)(K)))#

#n=0.2498580892# #mol#

#n=0.25# #mol# (rounded to#2# significant figures)