Carbon tetrachloride $(CC{l}_4)$ is diffusing through benzene $(C_6{H}_6),$ as the drawing illustrates. The concentration of $CC{l}_4$ at the left end of the tube is maintained at $1\mathrm{.}95{10}^{-2}k\frac{g}{m^3},$ and the diffusion constant is $24\mathrm{.}0{10}^{-10}\frac{m^2}{s}.$ The $CC{l}_4$ enters the tube at a mass rate of $5\mathrm{.}50{10}^{-13}k\frac{g}{s}.$ Using these data and those shown in the drawing, find $($a$)$ the mass of $CC{l}_4$ per second that passes point A and $($b$)$ the concentration of $CC{l}_4$ at point $A.$

$($a$)$ Number $$ Units $$

$($b$)$ Number $$ Units $$