Question

A buffer is created with 0.100 moles of HF and 0.100 moles of NaF in a...

A buffer is created with 0.100 moles of HF and 0.100 moles of NaF in a 1.00 L aqueous solution. This buffer has a pH of 3.15. How many moles of NaOH would you need to add to this buffer in order to obtain a solution with a pH of 3.80. (Ka of HF = 7.1 x 10–4)

Homework Answers

Answer #1

Given that Ka of HF =  7.1 x 10–4

Let us assume , moles of NaOH = x

   HF + NaOH -----------> NaF + H2O

0.1 x x

-------------------------------------------------------------------

0.1-x 0 x

Hence,

pH = -logKa + log [NaF]/[HF]

3.8 = -log (7.1 x 10–4 ) + log [x/0.1-x]

3.8 = 3.15 + log [x/0.1-x]         

x/0.1-x = 1.915

x = 0.1915 - 1.915 x

2.915x = 0.1915

x = 0.066

Therefore,

moles of NaOH required = 0.066 mol

  

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
A 1.00 L buffer solution is composed of 0.250 M HF and 0.250 M NaF. Calculate...
A 1.00 L buffer solution is composed of 0.250 M HF and 0.250 M NaF. Calculate the 13)______ pH of the solution after the addition of 0.150 moles of solid NaOH. Assume no volume change upon the addition of base. The Ka for HF is 3.5 × 10-4.
A)Calculate the pH of 0.100 L of a buffer solution that is 0.27 M in HF...
A)Calculate the pH of 0.100 L of a buffer solution that is 0.27 M in HF (Ka = 3.5 x 10-4 ) and 0.51 M in NaF?B)What is the pH after adding 0.004 mol of HNO3 to the buffer described in Part A? C)What is the pH after adding 0.004 mol of KOH to the buffer described in Part A?
10)You make a buffer - 0.7M HF (Ka=7.2x10^-4) and 0.8M NaF in 1300 mls of solution....
10)You make a buffer - 0.7M HF (Ka=7.2x10^-4) and 0.8M NaF in 1300 mls of solution. whats the ph? 11) You add 50 mls of 3M NaOH to this buffer. find the ph 12) You add 80 mls of HCl to this buffer. find the ph
A buffer was made by mixing 0.1070 moles of HF with .1147 moles of NaF and...
A buffer was made by mixing 0.1070 moles of HF with .1147 moles of NaF and diluting to exactly 1 liter. What will be the pH after addition of 10.00 mL of 0.2048 M HCl to 50.00 mL of the buffer? Ka(HF) = 3.500e-4. Note: only a portion of the original buffer is used in the second part of the problem. Answer is 3.154
A buffer solution was created by combining 0.700 moles of HCN and 0.900 moles of NaCN...
A buffer solution was created by combining 0.700 moles of HCN and 0.900 moles of NaCN in 1.00 L of water. How many moles of NaOH would be added to reach a pH of 9.75?
What volumes of 0.47 M HF and 0.47 M NaF must be mixed to prepare 1.00...
What volumes of 0.47 M HF and 0.47 M NaF must be mixed to prepare 1.00 L of a solution buffered at pH = 3.28? ka= 7.2 x 10^-4 for HF
A buffer solution was created by combining 0.700 moles of HCN and 0.900 moles of NaCN...
A buffer solution was created by combining 0.700 moles of HCN and 0.900 moles of NaCN in 1.00 L of water. How many moles of HCl would be added to reach a pH of 8.95?
A 350.0 mL buffer solution is 0.170 M in HF and 0.170 M in NaF. A)...
A 350.0 mL buffer solution is 0.170 M in HF and 0.170 M in NaF. A) What mass of NaOH could this buffer neutralize before the pH rise above 4.00? B) If the same volume of the buffer was 0.360 M in HF and 0.360 M in NaF, what mass of NaOH could be handled before the pH rises above 4.00?
0.75 moles of HF and 1.00 mole of NaF were added to 1.00 L of water....
0.75 moles of HF and 1.00 mole of NaF were added to 1.00 L of water. To this solution was added 0.300 mols of HCl. What was the final pH of the solution? Give your answer to two decimal places
Calculate the pH of a solution that is 0.200 M in NaF (aq) and 0.300 M...
Calculate the pH of a solution that is 0.200 M in NaF (aq) and 0.300 M HF (aq). Ka for HF is 3.5*10-4 Calculate the pH after 0.050 moles of NaOH is added to 1 L of the above solution. Please help thank you in advnce
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT