Lab Setup Question: Why was the CaCl2 Tube Used?

[apchemstudent]

From the attachment: the recorded data

Before CuO + porcelain boat = 62.869g
CaCl2 + U tube = 80.483g


After: Porcelain boat + contents = 54.869g
CaCl2 + U tube = 89.483g.


Why was the CaCl2 tube between the generator and the tube containing the porcelain boat?

a) to absorb evaporated HCl
b) to absorb evaporated H2O
c) to slow down the gases released
d) to absorb the evaporated Zn particles
e) to remove the initial air that passes through the tube

which one is the answer? Our teacher doesn't do much lab work with us so please help. thanks.

 

[apchemstudent]

does anyone know the answer to this problem? i don't understand it at all. Thanks.

 

[GCT]

Well, from a quick glance, here's my humble opinion:

a)it's seems that this is a possibility

b)Zn + HCl does not produce water, merely hydrogen gas and the resulting salt. If it isn't pure HCl, than it could be a possibility.

C)probably not, although not completely sure. The question, I believe, refers to the common ion effect.

D)should probably rule out this one. Zn gas particles exist in the form of ions and this is under high temperatures.

E)...by now, my guess seems to be A or B, more towards B, although I highly advise a second opinion.