Question

1) A buffer solution contains 0.388 M NH3. Determine the pH change when 0.088 mol NaOH...

1) A buffer solution contains 0.388 M NH3. Determine the pH change when 0.088 mol NaOH is added to 1.00 L of the buffer.

2) Determine the pH change when 0.070 mol HBR is added to 1.00 L of a buffer that is 0.49u M HF and 0.302 M in F-.

Please show work

Homework Answers

Answer #1

1) Buffer of weak base/conjugate acid : NH3/NH4+

Lets say we had equal concentrations of [NH3] = [NH4+] = 0.0388 M in the buffer initiallly,

initial pH of buffer = pKa of NH4+ = 9.25

When 0.088 mol NaOH has been added to 1 L buffer,

new [NH3] = (0.388 M x 1 L + 0.088 mol)/1 L = 0.476 M

new [NH4+] = (0.388 M x 1 L - 0.088 mol)/1 L = 0.3 M

new pH = pKa + log(NH3/NH4+)

pH = 9.25 + log(0.476/0.3) = 9.45

change in pH = final - initial = 9.45 - 9.25 = 0.2

2) Initial pH of buffer HF/F- (weak acid/conjugate base)

pH = pKa + log(F-/HF)

     = 3.17 + log(0.302/0.490)

     = 2.96

When 0.070 mol HBr is added to 1 L of buffer

new [F-] = (0.302 M x 1 L - 0.070 mol)/1 L = 0.232 M

new [HF] = (0.490 M x 1 L + 0.070 mol)/1 L = 0.560 M

new pH = pKa + log(F-/HF)

pH = 3.17 + log(0.2326/0.560) = 2.79

change in pH = final - initial = 2.79 - 2.96 = -0.17

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
1.) A buffer solution contains 0.455 M NH4Cl and 0.295 M NH3 (ammonia). Determine the pH...
1.) A buffer solution contains 0.455 M NH4Cl and 0.295 M NH3 (ammonia). Determine the pH change when 0.085 mol NaOH is added to 1.00 L of the buffer. pH after addition − pH before addition = pH change = 2.) Determine the pH change when 0.044 mol HNO3 is added to 1.00 L of a buffer solution that is 0.462 M in HF and 0.218 M in F-. pH after addition − pH before addition = pH change =
A buffer solution contains 0.257 M NH4Br and 0.482 M NH3 (ammonia). Determine the pH change...
A buffer solution contains 0.257 M NH4Br and 0.482 M NH3 (ammonia). Determine the pH change when 0.124 mol HBr is added to 1.00 L of the buffer. pH after addition − pH before addition = pH change = ?
A buffer solution contains 0.337 M KHSO3 and 0.289 M Na2SO3. Determine the pH change when...
A buffer solution contains 0.337 M KHSO3 and 0.289 M Na2SO3. Determine the pH change when 0.083 mol HBr is added to 1.00 L of the buffer.
A buffer solution contains 0.360 M KHCO3 and 0.352 M Na2CO3. Determine the pH change when...
A buffer solution contains 0.360 M KHCO3 and 0.352 M Na2CO3. Determine the pH change when 0.099 mol NaOH is added to 1.00 L of the buffer. pH after addition − pH before addition = pH change =
1. A buffer solution contains 0.476 M KH2PO4 and 0.202 M Na2HPO4. Determine the pH change...
1. A buffer solution contains 0.476 M KH2PO4 and 0.202 M Na2HPO4. Determine the pH change when 0.050 mol HClO4 is added to 1.00 L of the buffer. pH change = ______ 2. Determine the pH change when 0.077 mol HClO4 is added to 1.00 L of a buffer solution that is 0.331 M in CH3COOH and 0.304 M in CH3COO-. pH after addition − pH before addition = pH change =_____
1. A buffer solution contains 0.378 M KHCO3 and 0.268 M K2CO3. Determine the pH change...
1. A buffer solution contains 0.378 M KHCO3 and 0.268 M K2CO3. Determine the pH change when 0.094 mol KOH is added to 1.00 L of the buffer. pH after addition − pH before addition = pH change = 2. Determine the pH change when 0.066 mol HI is added to 1.00 L of a buffer solution that is 0.345 M in CH3COOH and 0.262M in CH3COO-. pH after addition − pH before addition = pH change =
A buffer solution contains 0.263 M CH3NH3Cl and 0.339 M CH3NH2 (methylamine). Determine the pH change...
A buffer solution contains 0.263 M CH3NH3Cl and 0.339 M CH3NH2 (methylamine). Determine the pH change when 0.076 mol HNO3 is added to 1.00 L of the buffer. pH after addition − pH before addition = pH change = A buffer solution contains 0.333 M NaH2PO4 and 0.221 M Na2HPO4. Determine the pH change when 0.046 mol HClO4 is added to 1.00 L of the buffer. pH change =
A buffer solution contains 0.484 M NaH2PO4 and 0.211 M K2HPO4. Determine the pH change when...
A buffer solution contains 0.484 M NaH2PO4 and 0.211 M K2HPO4. Determine the pH change when 0.054 mol HCl is added to 1.00 L of the buffer. ph change=
A 100 mL of buffer solution contains 0.100 M in NH3 (aq) and 0.100 M in...
A 100 mL of buffer solution contains 0.100 M in NH3 (aq) and 0.100 M in NH4Cl. (Q7 ‒ Q9) 7. Calculate pH of the buffer solution. 8. Calculate the change of pH when 4.00 mL of 0.100 M HCl (aq) is added to the buffer solution. 9. Calculate the pH of the solution when 4.00 mL of 0.100 M NaOH is added to the original buffer solution. Please show steps and explain so I can understand how. thank you
Determine the pH change when 0.081 mol HI is added to 1.00 L of a buffer...
Determine the pH change when 0.081 mol HI is added to 1.00 L of a buffer solution that is 0.349 M in HCN and 0.342 M in CN-.
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT