HCl and NH3 react to form NH4Cl, a white solid. If NH3 and HCL are introduced at opposite ends of a 60.0cm tube, how far from the HCl end will the white ring of NH4Cl form?
The answer is 24.3cm but I have no clue on how to solve thing. Can someone please explain it to me. Thanks.
2006-12-18 01:33:09 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
This is a diffusion problem.
Let H be the point of HCl inlet.
Let N be the point of NH3 inlet.
Let the point of meeting be P at which NH4Cl is formed
Simplyfying Grahams law we get.
l(HP)/l(NP)= root M(NH3)/ root M(HCl)
M(NH3)=17
M(HCl)=36.5
l(HP)/l(NP)= sqrt(17/36.5) = 0.682
Let l(HP)=x
x/(60-x)=0.682
Solving you get x=24.337
2006-12-18 01:38:31 · answer #1 · answered by Som™ 6 · 0⤊ 0⤋
Here's a clue: diffusion rate proportional to 1/sq.rt of gas density.
HCl - MWt 36.5 - sq.rt = 6.04
NH3 - MWt 17 - sq.rt = 4.12
6.04 + 4.12 = 10.16
4.12/10.16 = 0.4055
0.4055*60cm = 24.3cm
QED
2006-12-18 09:48:47 · answer #2 · answered by JJ 7 · 0⤊ 0⤋