# chemistry

posted by .

A buffer solution is 1.00 M in NH3 and 1.10 M in NH4Cl. If 0.230 moles of NaOH are added to 1.00 L of the buffer, what is its pH? Assume the volume remains constant. Kb of NH3 = 1.8 multiplied by 10-5.

• chemistry -

Use the Henderson-Hasselbalch equation.
NH3 + H^+ ==> NH4^+
initial:
NH3 = 1.00 M from the problem.
H^+ = whatever, but can be calculated if you want to know.
NH4^+ = 1.10 M from the problem.
Just for the fun of it I plugged in 1.00 for B and 1.10 for acid and found pH = 9.21.
For the problem, if we add 0.230 moles NaOH, we must REMOVE 0.230 H^+, which shifts the above equilibrium to the left. NH4^+ is decreased by 0.230 and NH3 is increased by 0.230.
Final moles NH3 = 1.00 + 0.230 = ??
Final moles NH4^+ = 1.10 - 0.230 = ??
Substitute into HH equation and solve. I get something close to 9.4 but check me out.

## Similar Questions

1. ### chemistry

Will this solution form a buffer? 100 mL of .10 M NH3; 100 mL of .15 M NH4Cl Work: NH3= .01 moles NH4Cl= .015 moles .... not sure what else to do. I think we use the H-H equation, but I don't know how to find pKa, or even what pKa
2. ### chemistry

A buffer solution contains 0.200 M NH3 and 0.250 M NH4Cl. What is the pH of the buffer solution after the addition of 10.0 mL of 0.100 M NaOH to 50.0 mL of the buffer?
3. ### CHEMISTRY

If one added 130 mL of 2 M NaOH to 1 L of a buffer composed of 2.3 M NH3 and 3.2 M NH4Cl, what would be the pH of the resulting solution?
4. ### CHEM 112

A buffer solution is 1.40 M in NH3 and 1.00 M in NH4Cl. If 0.100 moles of NaOH are added to 1.00 L of the buffer, what is its pH?
5. ### CHEM 112

A buffer solution is 1.40 M in NH3 and 1.00 M in NH4Cl. If 0.100 moles of NaOH are added to 1.00 L of the buffer, what is its pH?
6. ### chemistry

How many grams of NH4Cl must be added to 0.490 L of 1.70 M NH3 solution to yield a buffer solution with a pH of 9.40?
7. ### Chemistry

Q1: You wish to prepare a buffer solution with pH = 11.10. What volume of 6.0 M HCl would you add to 500 mL of 0.10 M (C2H5)2NH to prepare the buffer?
8. ### Chemistry

Q1: You wish to prepare a buffer solution with pH = 11.10. What volume of 6.0 M HCl would you add to 500 mL of 0.10 M (C2H5)2NH to prepare the buffer?
9. ### chem

How many grams of NH4Cl must be added to 0.560 L of 1.90 M NH3 solution to yield a buffer solution with a pH of 8.50?
10. ### Chemistry

A buffer solution is prepared by mixing 50.0 mL of 0.300 M NH3 with 50 mL of 0.300 NH4Cl. The pKb of NH3 is 4.74. NH3 + H2O-> NH4+ +OH- 7.50 mL of 0.125 M HCl is added to the 100 mL of the buffer solution. Calculate the concentration …

More Similar Questions