Acetone is evaporating with a mass flow rate of $1$ gram per minute into a room that is $1m^3$ in

size. The room has a ventilation rate, $V^{},$ of $1\frac{m^3}{m}in.$

a$.$ Compute the steady$-$state mass concentration of acetone in the room. Note that $m^{}=V^{}C,$

where $C$ is the mass concentration, $V^{}$ is the volumetric flow rate, and $m^{}$ is the mass flow rate.

b$.$ Assuming the air in the room is initially free of acetone, compute the time necessary for

benzene to reach $95\%$ of the steady$-$state concentration.