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Topic: Analysis of an aluminum-zinc alloy using HCl  (Read 22696 times)

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Offline buckminsterfullerene

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Analysis of an aluminum-zinc alloy using HCl
« on: November 05, 2007, 09:24:42 PM »
errmm.... the packet that is supplying me with the information on how to solve these kind of problems is making little sense to me, and I am supposed to write a lab report on that, can't really accomplish that unless I comprehend what is going on and how do the equations, which at this point seem to be all over the packet, work.

a link to a site that has helpful information is welcomed, but if you know anything to the perspective, please respond, and thanks in advanced.

-Daniel Garcia
currently a student attending high school in South Florida, capital of all the hurricanes that come through the US, and the sunshine state.  My interests falls into electrochemistry going to renewable resources of energy, i like hydrogen fuel cells and solar energy

Offline buckminsterfullerene

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Re: Analysis of an aluminum-zinc alloy using HCl
« Reply #1 on: November 05, 2007, 11:36:03 PM »
perhaps some information might help.

it seems, after reading the packet a couple times, the main equation to be used in order to determine is going to be:

n(H2) = (0.0556 moles H2 / gAl) * X*gAl + (0.0153 moles H2 / gZn) * (mass of sample - X)

where X is apparently the mass of Aluminum, (mass of Al -X) is the mass of Zinc

that is that for the equation they give that I still have to try and make some sense about.

as for the value that I have acquired through the experimentation, at least the values that are significant:
trial 1
mass of alloy = .104 g
displaced water = 122.5 mL (we are to assume density of the water is 1.00 g/mL to determine the the amount of hydrogen gas available)
the temperature was 22 Celsius (of the water that is)
barometric pressure = 761.4 mm Hg
pressure of water = 19.87 mm Hg
pressure of hydrogen = 741.6 mm Hg

and I am supposed to determine the mass of Al, Zn the percentage of Al and Zn.

I am not asking for you to do the work, but to tell me how this works, I am completely lost...

(P.S. use ideal gas laws... do not get too technical, this is a beginners chemistry course, sort of)

if you feel like giving the response rather than explaining that will also help, I could use a response to try and work it backwards, answers by themselves are pretty useless for me though as I have to also write a lab report explaining everything.
uggh...
currently a student attending high school in South Florida, capital of all the hurricanes that come through the US, and the sunshine state.  My interests falls into electrochemistry going to renewable resources of energy, i like hydrogen fuel cells and solar energy

Offline buckminsterfullerene

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Re: Analysis of an aluminum-zinc alloy using HCl
« Reply #2 on: November 06, 2007, 10:34:59 AM »
perhaps some information might help.

it seems, after reading the packet a couple times, the main equation to be used in order to determine is going to be:

n(H2) = (0.0556 moles H2 / gAl) * X*gAl + (0.0153 moles H2 / gZn) * (mass of sample - X)

where X is apparently the mass of Aluminum, (mass of Al -X) is the mass of Zinc

that is that for the equation they give that I still have to try and make some sense about.

as for the value that I have acquired through the experimentation, at least the values that are significant:
trial 1
mass of alloy = .104 g
displaced water = 122.5 mL (we are to assume density of the water is 1.00 g/mL to determine the the amount of hydrogen gas available)
the temperature was 22 Celsius (of the water that is)
barometric pressure = 761.4 mm Hg
pressure of water = 19.87 mm Hg
pressure of hydrogen = 741.6 mm Hg

and I am supposed to determine the mass of Al, Zn the percentage of Al and Zn.

I am not asking for you to do the work, but to tell me how this works, I am completely lost...

(P.S. use ideal gas laws... do not get too technical, this is a beginners chemistry course, sort of)

if you feel like giving the response rather than explaining that will also help, I could use a response to try and work it backwards, answers by themselves are pretty useless for me though as I have to also write a lab report explaining everything.
uggh...


n(H2) = (0.0556 moles H2 / gAl) * X*gAl + (0.0153 moles H2 / gZn) * (mass of sample - X)
never mind, that equation just got me really confused, but it was simple after all, I just thought that I had three different unknown values and did not realize that whoever wrote the packer wrote what X was in the equation itself rather then outside, lol.

X is the mass of Aluminum so in reality the equation comes out being


n(H2) = (0.0556)X + (0.0153)(mass of sample - X)
and I would solve for X, very simple indeed, lol.
currently a student attending high school in South Florida, capital of all the hurricanes that come through the US, and the sunshine state.  My interests falls into electrochemistry going to renewable resources of energy, i like hydrogen fuel cells and solar energy

Offline ajrobb9109

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Re: Analysis of an aluminum-zinc alloy using HCl
« Reply #3 on: January 04, 2009, 02:22:06 PM »
so how would go about finding the %Al?

Offline artem.metelskiy

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Re: Analysis of an aluminum-zinc alloy using HCl
« Reply #4 on: April 20, 2011, 08:50:12 PM »
We are going to do this lab next week and I'm very confused about all those formulas

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