Calculating Formic Acid & Sodium Formate for pH Change

Thread starter zeshkani
Start date Oct 27, 2007
Tags

Acid Change Ph Sodium

AI Thread Summary

To maintain a buffer solution at pH 3.35 with minimal pH change upon adding 0.02 moles of strong acid, the Henderson-Hasselbalch equation is essential for calculating the required moles of formic acid and sodium formate. The buffer capacity must be sufficient to resist a pH change of less than 0.02, which involves determining the appropriate ratio of the acid to its conjugate base. The discussion highlights the need for a systematic approach to set up the calculations, focusing on the buffer equation and the desired pH stability. Understanding the relationship between pH, pKa, and the concentrations of the components is crucial for solving this problem effectively. Proper application of these principles will yield the necessary quantities of formic acid and sodium formate.

Oct 27, 2007

zeshkani

Homework Statement

A solution is to be buffer at pH = 3:35 with formic acid and formate.
(a) How many moles of formic acid and sodium formate are needed if the solution is to change pH by < 0:02
for the addition of 0.02 moles of strong acid?

i need help how to set up a problem like this, i don't even know how to approche it !

Physics news on Phys.org

Oct 29, 2007

Stevedye56

I think this might help. Henderson-Hasselbalch

Thread 'Confusion regarding a chemical kinetics problem'

TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...

View full post »

Thread 'Prove that evolution is constant (Provide at least two arguments to support your position)'

I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...

View full post »