$($Example $1\mathrm{.}13)$ Calculate gas viscosity at $250F$ and $2,500$ psia for sour$-$gas sample described in Examples $1\mathrm{.}2$ and $1\mathrm{.}8$ with the Lee et al$.$ method. Pseudocritical properties corrected for $H2S$ and $CO2$ were estimated in Example $1\mathrm{.}2,$ and $z-$factor was estimated in Example $1\mathrm{.}11.$ Ignore the nitrogen contamination.

$M=23l\frac{b}{l}b-$mol.

$P_{pc}=714\mathrm{.}9$ psia.

$T_{pc}=372\mathrm{.}2R.$

$z=0\mathrm{.}87.$