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Topic: I messed up !!!  (Read 4577 times)

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Offline Tybalt

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I messed up !!!
« on: May 14, 2008, 06:58:04 PM »
I was running through my numbers to complete my TITRATION lab report and realized that I messed up right out of the gate.  In creating a 0.1 M CuCl2 * 2H2O solution  I used 1.525g instead of 1.705g, shorting my solution about 0.180g. Making the concentration less than 0.1M, right?

My main question, is there some way to mathematically calculate the correct amount (mL) of NaOH I was to burette into the CuCl2 * 2H2O solution?

Redoing the lab isn't a possibility...

Offline Guitarmaniac86

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Re: I messed up !!!
« Reply #1 on: May 14, 2008, 07:02:35 PM »
I was running through my numbers to complete my TITRATION lab report and realized that I messed up right out of the gate.  In creating a 0.1 M CuCl2 * 2H2O solution  I used 1.525g instead of 1.705g, shorting my solution about 0.180g. Making the concentration less than 0.1M, right?

My main question, is there some way to mathematically calculate the correct amount (mL) of NaOH I was to burette into the CuCl2 * 2H2O solution?

Redoing the lab isn't a possibility...

Yes there is.

I can give you the formula to manipulate but then you wont really learn anything other than manipulating results.

I got in serious trouble with my university for mathematically working out the correct values for a titration.

Edit:

Use the results you have and in the evaluation, explain what went wrong.

Edit 2:

I feel bad now.

Heres a hint: How do you work out concentrations, volumes and moles from a titration? If you know that, you have your answer. Also, look at the reaction... It will help if its balanced and something is worked out to do with ratios of something....
Don't believe atoms, they make up everything!

Offline Tybalt

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Re: I messed up !!!
« Reply #2 on: May 14, 2008, 07:12:22 PM »
To some extent your right, it wouldn't be very constructive if you had handed me the information before I preformed my experiment, to which I would have blown off the lab completely.  But given that I've already gone through the experiment and learned the error of my mistake, theres no harm in helping correct my error.

Offline Tybalt

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Re: I messed up !!!
« Reply #3 on: May 14, 2008, 07:16:59 PM »
Quote
Use the results you have and in the evaluation, explain what went wrong.

I didn't even think of that, I think I'll use it.

Offline Guitarmaniac86

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Re: I messed up !!!
« Reply #4 on: May 14, 2008, 07:20:35 PM »
To some extent your right, it wouldn't be very constructive if you had handed me the information before I preformed my experiment, to which I would have blown off the lab completely.  But given that I've already gone through the experiment and learned the error of my mistake, theres no harm in helping correct my error.

Well...

OK.

CuCl2 . 2H2O + 2NaOH --> Cu(OH)2 + 2NaCl + 2H2O

The reaction is 1 : 2

Use Moles = Concentration x Volume (cm3) / 1000

To work out the number of moles of CuCl2 . 2H2O

However many moles of that you have, you should have 2 x number of moles for NaOH

Subsitute that into the equation:

Volume = Moles x 1000 / Concentration (volume in cm3

This should give you the theoretical volume for the NaOH

You havent given the volume so I cant give numerical values.

Sorry if I came across arsey earlier. I meant nothing by it.
Don't believe atoms, they make up everything!

Offline Tybalt

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Re: I messed up !!!
« Reply #5 on: May 14, 2008, 07:30:51 PM »
No harm no foul.  I owe you one.


-Tybalt

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