Pyridine is a conjugate base which reacts with h to form pyridine hydrochloride. the hydrochloride dissociates to yield h' with a pkof 5.36. describe the preparation of a pyridine buffer at ph 5.2 starting with 0.1m pyridine and 1.om hci. you may start with one liter of the 0.1 m pyridine.

To one liter of the 0.1 M pyridine you need to add 41 mL of 1,0M HCl to obtain a buffer at 5,2

Explanation:

The reaction is:

pyridine-H⁺ ⇄ pyridine + H⁺ pka = 5,36; k =

Using Henderson-Hasselbalch formula:

5,2 = 5,36 + log

0,692 = (1)

As total intial moles are 0,1:

0,1 = Py-H⁺ moles + Py moles (2)

Replacing (2) in (1) final moles of both Py-H⁺ and Py are:

Py: 0,059 moles

Thus:

Py-H⁺: 0,041 moles

Moles in reaction are:

Py: 0,1-x moles

H⁺: Y-x moles Y are initial moles of H⁺

Py-H⁺: x moles

Knowing x = 0,041 moles, pyridine volume is 1L and HCl molarity is 1 mol/L and [H⁺] =

=

Y = 0,04100605 moles≡ 41 mL of 1,0M HCl

I hope it helps!

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year