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burtwood Offline
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Age: 32

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Join Date: April 21st 2009

Chemistry Help! Molar Concentrations! - May 28th 2009, 12:18 AM

I have to do a lab that has to be handed in soon so any help would be greatly appreciated. The question says: A sample of vinegar from the school cafeteria is diluted by a factor of 10 to make a 100.00 mL solution. The diluted solution is titrated with a standard sodium hydroxide solution using phenolphthalein is the indictator. What is the molar concentration of acetic acid in a sample of vinegar?

My oberservations are:
NaOH= 0.098 g/mol
NaOH= 60.00 mL

Vinegar = 50.00 mL

Trial 1
Final Buret Reading (mL) = 11.30
Inital Buret Reading (mL) = 2.20
Volume of HCl (aq) added (mL) = 9.10

Trial 2
Final Buret Reading (mL) = 20.30
Inital Buret Reading (mL) = 11.30
Volume of HCl (aq) added (mL) = 9.00

Trial 3
Final Buret Reading (mL) = 29.20
Inital Buret Reading (mL) = 20.30
Volume of HCl (aq) added (mL) = 9.10

Help me PLEASE!