At #"STP"#, a gas will contain approximately a volume of #22.7 \ "L"#. Click here for the explanation.

So here, we need to convert #3.4 \ "g"# of carbon dioxide into moles.

Carbon dioxide has a molar mass of #44 \ "g/mol"#. So here, there exist,

#(3.4color(red)cancelcolor(black)"g")/(44color(red)cancelcolor(black)"g""/mol")=0.0772727273 \ "mol"#

And so, the molar volume is:

#0.0772727273color(red)cancelcolor(black)"mol"*(22.7 \ "L")/(color(red)cancelcolor(black)"mol")=1.75409090971 \ "L"#

#~~1.755 \ "L"#