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Way Below Xero
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Joined: 26 May 2003
Posts: 32
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 Posted: Sun, 10 Aug 2003 23:19:21 UTC Post subject: Volumetric Analysis |
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THe following proceedure was carried out to determine the % of Fe in a piece of steel.
Step 1: A piece of steel weighing 2.482 g was dissolved in acid and made up to a volume of 200.00 mL in a volumetric flask.
Step 2: 25.00 mL aliquots of this solution were titrated with acidified potassium permanganate solution.
Reactions occurs is: 5Fe(2+) + MnO4(-) + 8H(+) --> 5Fe(3+) + Mn(2+) + 4H2O
Average titre to be used: 16.30 mL
OK! Question is: Calculate the % of iron by mass in original sample of steel.
HELP! |
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Eccentric
Senior Member
Joined: 05 Jun 2003
Posts: 80
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| Posted: Mon, 11 Aug 2003 10:47:44 UTC Post subject: |
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| What is the molarity of the potassium permanganate? |
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Way Below Xero
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Joined: 26 May 2003
Posts: 32
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| Posted: Mon, 11 Aug 2003 23:56:04 UTC Post subject: |
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| 0.0150 mol/L |
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Eccentric
Senior Member
Joined: 05 Jun 2003
Posts: 80
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| Posted: Tue, 12 Aug 2003 12:23:42 UTC Post subject: |
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Number of moles of  = Volume x concentration
5Fe(2+) + MnO4(-) + 8H(+) --> 5Fe(3+) + Mn(2+) + 4H2O
Molar ratio of Fe with = 1:5 
Number of moles of Fe =  of that of you have the number of moles of Fe IN THE 25 ML sample. Multiply this by 8 to get the number of moles in the 200 ml. Can you do the rest on your own? Hope this helps.
Regards,
Yousif |
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