Question 169514
Working Eqn -----> {{{PV=nRT}}}
where--->{{{system(P=101.325atm,V=(L),n=moles,R=0.0821=GasConstant,T=273.15(K))}}}
*Note: At STP, {{{Pressure}}} is atmospheric Pressure & {{{Temperature}}} is Freezing Point.
Solving for {{{n}}}?
{{{n=mass/highlight(MW)}}}
where, {{{MW=(NumberofAtoms)(AtomicWeight)}}}
Via Periodic Table, Atomic Weight of {{{Flourine}}} = "19." 
So, {{{MW=2*19=38}}}
Subst. ------> {{{n=86.8cross(g)/(38cross(g)/mol))}}}
{{{n=2.28}}}
.
Going back Working Eqn,
{{{101.325(V)=(2.28)(0.0821)(273.15)}}}
{{{cross(101.325)V/cross(101.325)=cross(51.13)0.5046/cross(101.325)}}}
{{{highlight(V=0.5046L)}}}, Answer
.
Thank you,
Jojo