Calculating pH of a solution with two weak acids and a strong base

  • Thread starter Thread starter sparkle123
  • Start date Start date
  • Tags Tags
    Acids Base Weak
AI Thread Summary
To calculate the pH of a solution containing two weak acids (acetic acid and hydrogen sulfide) and a strong base (sodium hydroxide), one must consider the neutralization reactions and the remaining concentrations of the acids after partial neutralization. The strongest acid, acetic acid, will be neutralized first, followed by hydrogen sulfide. The Henderson-Hasselbalch equation can be applied to determine the pH after accounting for the amounts of each acid that remain unneutralized. It is essential to calculate the extent of neutralization for each acid based on their dissociation constants (Ka values). Ultimately, the solution's pH can be derived from the remaining concentrations of the weak acids and their respective dissociation equilibria.
sparkle123
Messages
172
Reaction score
0

Homework Statement


0.5332 M CH3COOH
0.1219 M CH3COONa
0.100 M H2S

0.41452 M NaOH

what is the pH of the resulting solution?

Homework Equations



CH3COOH Ka=1.75E-5
H2S Ka1=9.6E-8, Ka2=1.3e-14

The Attempt at a Solution



I know that neutralisation will occur, but there is not enough strong base to neutralize all of the weak acids. How do you know how much of each acid the base will neutralize? How would you calculate pH then? I know if there was one weak acid you could use the Hendelson-Hasselbach equation but I don't know what do with two weak acids :(
 
Physics news on Phys.org
Strongest acids are neutralized first.

Idea of using Henderson-Hasselbalch equation is a right one, just start with the first hint and see what you get after using all base.
 
yup
borek has provided u with almost all of the reqd. hints!:-p
 
Thread 'Confusion regarding a chemical kinetics problem'

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 »

Similar threads

Chemistry Is pH of strong acid strong base titration always 7 at stoichiometric point?
Replies
2
Views
1K
Chemistry Are there typos in this snippet causing confusion?
Replies
2
Views
1K
Chemistry How to take into account autoprotolysis in weak base solution?
Replies
8
Views
2K
Chemistry Understanding how to calculate pH of a buffer solution
Replies
2
Views
1K
Chemistry How to calculate pH at equivalence point using this alternative?
Replies
7
Views
1K
Chemistry Comparing methods of computing pH at equivalence point in titration
Replies
4
Views
1K
Chemistry Moles of NaOH to Create Buffer Solution pH=6 in 0.42M Ethanoic Acid
Replies
3
Views
3K
Which formula to use to find the pH of a solution?
Replies
20
Views
3K
Titration of Sulfurous Acid: Calculating pH with Ka Values
Replies
3
Views
2K
How Does Pre-existing CH3COONa Affect Buffer pH Calculation?
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top