Struggles in equilibrium calculation from general chemistry class

[daydayup]

Hi! I am a new user of this forum. Recently I have been studying the general Chemistry class and I have been struggling with the calculation of equilibrium.

In this slide, it has declared that 10 mmol H+ is added to 1L of solution, with the buffer 0.1M HCO3 existing. 

My thinking would be like that :

pH = pKa + log (conjugate base/acid), where pH=pKa=6.1
Thus, log (conjugate base/acid) =0

conjugate base [HCO3-] / acid [H+] = 1

When there is 0.1M HCO3, there would be 0.1M H+, however, I cannot drive to the same conclusion as my lecturer. 

I would like to ask how the lecturer could conclude that log (conjugate base/acid) =1 and why [buffer] = [acid] + [conjugate base].

I know that my questions seem stupid but I really struggle with the equilibrium calculation and would be much appreciated by anyone who wants to give a helping hand. If there is any textbook/ online resource that could help me learn this course (or biochemistry), I would also go and read it 😉 

Thanks!

[studiot]

Welcome.

 

I see from this question you are studying Henderson Hasselbalch so you must already have quite a bit of simpler stuff under your belt.

You also seem to indicate that you are chemistry as subsidiary to some bio or medical course.

In which case this book will help greatly.

The relevant section here

 

 

I don't have more time this morning, but I see there are other chemists about.

 

Also I recommend you ask a moderator to move this to chemistry since we can work through it there.

Homework help is more restrictive and your question is not homework.

[daydayup]

28 minutes ago, studiot said:

 

I don't have more time this morning, but I see there are other chemists about.

 

Also I recommend you ask a moderator to move this to chemistry since we can work through it there.

Homework help is more restrictive and your question is not homework.

Thanks for your kind help! You are correct- I am studying biochemistry, and some biomedical science right now:) (and seems I am not getting so well with the chemistry foundations)
I could check out the useful textbook later today and hope it can help figure out what happening on this topic:) 

Just now I am reading the book General Chemistry-Principles and Modern Applications and seems I have to know more on the topic, maybe I will come back later today to see if I have any idea on this question (so far I still don't what going on and didn't get what kind of calculation has been done...)

I could try to reach the moderator to move it to the chemistry forum (but I needed some time to figure out how to reach the moderator...), hope you have a nice day anyway:)