Compound A diffuses through a $4-$cm$-$long tube and reacts as

it diffuses. The equation governing diffusion with reaction is

D

d$2$

A

dx$22$ kA $50$

At one end of the tube, there is a large source of A at a concentra$-$

tion of $0\mathrm{.}1$ M$.$ At the other end of the tube there is an adsorbent

material that quickly absorbs any A$,$ making the concentration $0$ M$.$

If D $51\mathrm{.}531026$

cm$2$

$/$s and k $5531026$

s$21$

$,$ what is the concen$-$

tration of A as a function of distance in the tube?