Chemical Forums

Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: bowlbase on April 08, 2012, 01:41:35 PM

Title: Borax and HCl titration
Post by: bowlbase on April 08, 2012, 01:41:35 PM
Working on a lab and having trouble figuring out how to fill in the blanks of my table. The lab was diluting borax in a solution of DI water and heating up 4 test tubes to 4 different temperatures. After heating we placed a color indicator in the tubes and titrated with HCl. I know volume of HCl until color change and the molarity of the HCl. Given this information how can I find the number of moles or concentration of my B2-? If borax was a strong base I know I could say that at the equivalence point (color change) my number of moles H and number of moles B are equivalent. But since it is a weak base I don't know how to figure it out.

So this is all the info I have:
.2M HCl
First titration: 294.75 kelvin, 17mL HCl, ~0.0034mole H.

and 39.121g Borax(NA2B4O7 10H2O) was split among several test tubes so the amount of Borax in each is unknown.

Thanks for the guidance.