We are given the #molecules (4.00x10^23) but we need moles so this is the formula we use
N= #molecules/6.02x10^23
4.00x10^23/6.02x10^23
N= 0.66
Now we can use the formula for STP
N=v/22.7
So we rearrange the formula like so;
V=nx22.7
V= 0.66 X 22.7
Therefore the volume equals
14.98L
I hope this helps