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# Final pH of Tris.HCl buffer

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Calculate the final pH of 25 mL of buffer 0.1M Tris.HCl/Tris buffer, pH=6.60 after the addition of 1.00mL of 0.1M NaOH. pKa is 8.08.
use the 0.10M Tris.HCl and 0.10M Tris to prepare 100mL, pH=6.6 solution. it calculated by pre-lab, it need 96.8 mL 0.10M Tris.HCl and 3.2mL Tris. and take 25mL pH=6.6 solution, then add 1mL of 0.1M NaOH. Show the final pH

I used similar to the previous problem steps get 6.97, is it right?

https://brainmass.com/chemistry/acids-and-bases/final-ph-tris-hcl-buffer-547195

#### Solution Preview

I'm assuming your pre-lab calculations are correct. (If you need me to check your pre-lab calculations as well, do create a new posting).

100 mL of buffer contains 96.8 mL x 0.1 mmol/mL = 9.68 mmol of Tris.HCl

Hence 25 mL of ...

#### Solution Summary

The pH of a Tris.HCl buffer is calculated after addition of NaOH.

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