  In this work, we use the Green-Kubo method to study the bulk viscosity of
various dilute gases and their mixtures. First, we study the effects of the
atomic mass on the bulk viscosity of dilute diatomic gas by estimating the bulk
viscosity of four different isotopes of nitrogen gas. We then study the effects
of addition of noble gas on the bulk viscosity of dilute nitrogen gas. We
consider mixtures of nitrogen with three noble gases, viz., neon, argon, and
krypton at eight different compositions between pure nitrogen to pure noble
gas. It is followed by an estimation of bulk viscosity of pure oxygen and
mixtures of nitrogen and oxygen for various compositions. In this case, three
different composition are considered, viz., 25\% N$_2$ + 75\% O$_2$, 50\% N$_2$
+ 50\% O$_2$, and 78\% N$_2$ + 22\% O$_2$. The last composition is aimed to
represent the dry air. A brief review of works that study the effects of
incorporation of bulk viscosity in analysis of various flow situations has also
been provided.
