Answer
$23.2psi$
Work Step by Step
We know that
$PV=nRT$
But $n=\frac{m}{M}$ Where $m$ and $M$ are given mass and molar mass respectively
$\implies PV=\frac{mRT}{M}$
This can be rearranged as
$P=\frac{mRT}{VM}$
We plug in the known values to obtain:
$P=\frac{16.0\times 0.08206\times 298}{3.45\times 44.0095}=2.5769atm$
Now we convert pressure from atm to psi
$P=2.5769atim\times \frac{14.7psi}{1atm}=37.9psi$
Now we can find the gauge pressure as
$37.9psi-14.7psi=23.2psi$
