Homework Help: Chemistry

Posted by June on Thursday, July 19, 2012 at 8:43pm.

A buffer system contains 0.25M NH4+ and 0.19M NH3. pka of NH4 is 9.25.

How many moles of NaOH must be added to 1.00L of this solution to increase the pH to 9.25?

Chemistry - DrBob222, Thursday, July 19, 2012 at 9:10pm
mol NH3 = M x L = 0.19*1 = 0.190
mol NH4^+ = 0.25*1 = 0.250
-----------------
........NH4^+ + OH^- ==> NH3 + H2O
I.....0.250.....0......0.190
add..............x............
C.......-x......-x.......+x
E.....0.250-x.....0......0.190+x
Substitute into the Henderson-Hasselbalch equation and solve for x = mol NaOH added to 1L buffer to make pH = 9.25

Answer this Question

Related Questions

CHEMISTRY - HOW MANY MOLES OF NH3 WOULD BE FORMED FROM 50 GRAMS OF (NH4)2SO4 IN ...
chemistry - i need help with finding the ph of a buffer solution initially ...
chemistry - i need help with finding the ph of a buffer solution initially ...
Chem - Calculate the [NH4+] in solution that is 0.25 M NH3 and 0.20 M NaOH. (Kb ...
Chem I - Calculate the pH of two buffer systems to compare the differences in pH...
chemistry - Is this a buffer system? NH3/(NH4)2SO4? It is formed by mixing NH3 (...
Chemistry - How do you calculate the number of moles of NaOH to add to a liter ...
Chemistry - Rank the following fertilizers in decreasing order of mass ...
Science - Which pairs of substances will form a buffer when mixed in equal ...
chemistry-Buffer Q - You have a solution of .5 L of 1.74g of NH3 and 4.15g of (...

For Further Reading

First Name:
School Subject:
Answer: