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Wed 11 May, 2005 05:53 pm
I have a lab to do for chemistry. I have to determine the concentration of a sample of HCL. I have to come up with a procedure on how to find it. The equipment avaliable are the following:
100ml/600ml Beaker
100ml/10ml graduated Cylinder
Bunsen Burner and hose
Analytical Balance
Pipet(s)
Theromometer
Barometer
15ml of HCL of unknown concentration
Excess sodium chloride
Excess magnesium metal
Excell acetic acid
Tap/Distilled Water
I do not know where to start of which items to use to determine the concentration. Please Help!!
I can't give the procedure off the top of my head, but how about a burette, a known concentration of, say sodium hydroxide, and an indicator such as pheonthayline (pardon my spelling here)? In other words, a straight forward titration. Or is all that other stuff supposed to be part of the challenge?
You can only use the items given
Afraid not. Maybe someone else can do it without knowing when the HCl is neutralized, but it's beyond me. Sorry.
I'm thinking of reacting magnesium with HCl. Weighing the magnesium before and after mixing with a known quantity of HCl solution could be used to determine the amount of HCl available.
Magnesium reacts with the HCl to produce mag-chloride (and I believe hydrogen gas). This is a very complete reaction (going to the right) So introduce excess magnesium and determine the amount consumed in the reaction. Since the magnesium HCl reaction is complete, make sure the limiting reactant is HCl.
Rap
thanks alot thats just what i wanted to know!!!
You want to use a meathod call titration. You have all the apparatus. Thats when you have a measured amount of solution with unknown concentration (HCl) and you add it to a known volume of a second solution until the reaction is complete. The HCl's (the titer) concentration can then be calculated.
It's to compicated to explain in words and you will probably get lost along the way. So look at this:
Titration (How too)
That is what he wants, but not what the assignment calls for, Red. That's why I had to admit failure.
Welcome to a2k, both of you.
Thanks for all ur help, the lab was a success!!! Now I can do the stoiceometry to find the concentration
Right sorry about that. Well thats how I would do it.
Glad it worked out anyway/
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