Suppose you start with a solution of 1M NaF and are trying to make a buffered solution. Which of the following would you be able to add to the solution to make a buffer?
will make a buffer or will not make a buffer: BaCl2
will make a buffer or will not make a buffer: HCl
will make a buffer or will not make a buffer: NaOH
will make a buffer or will not make a buffer: HI
will make a buffer or will not make a buffer: HF
will make a buffer or will not make a buffer: HBr
HF and NaF – classic weak acid (HF) and its conjugate base (F- ) states “equal numbers of moles of each”.
Suppose you start with a solution of 1M NaF and are trying to make a buffered...
Which of the following mixtures may be act as a buffer solution? A) HBr, NaBr B) HF, NaF C) HCl, NaCl D) HI, NaI
A 1.50 L buffer solution is 0.250 M in HF and0.250 M in NaF. Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH. Assume no volume change upon the addition. The K_a for HF is 3.5 times 10^-4. 3.63 3.57 3.34 3.46 4.37 Which of the following conjugate pairs would be best for preparing a buffer solution at pH 4.0? HCN K_a = 6.2 times 10^-10 HNO_2 K_a = 7.1 times 10^-4 NaCI and...
Consider 1.0 L of a solution which is 0.80 M HF and 0.55 M NaF (K for HF - 7.2x104). Part 1 Calculate the pH of this solution. pH- Part 2 Calculate the pH after 0.10 mol of HCl has been added to the original buffer solution. Assume no volume change on addition of HCI. pH- Part 3 Calculate the pH after 0.20 mol of NaOH has been added to the original buffer solution. Assume no volume change on addition...
3. To make a buffer solution, you can start with a solution of a known number of moles of the base form (A) and add a strong acid until you have neutralized the correct number of moles of the base to have the correct A HA ratio for the buffer you require. For the example using HF in the background information: a. How many moles of the base form (A) are required to start? HINT: The acid form (HA) will...
How many moles of HCl need to be added to 200.0 mL of a 0.200 M solution of NaF to make a buffer with a pH of 3.60? (Ka for HF is 6.8 x 10-4)
You need to make a buffer solution with pH of 8.0. You have the following reagents on your shelf: HC3H5O3 Ka=1.4*10-4 NaF HF Ka=6.6*10-4 Tris-base HC2H3O2 Ka=1.8*10-5 NH3 HClO Ka=2.9*10-8 NaC2H3O2 Tris-HCl Ka=8.3*10-9 NaClO NH4Cl Ka=5.6*10-10 NaC3H5O3 a) Which reagents would you use to make the buffer solution. Briefly explain why you would choose these. b) In what ration of molar concentrations would you combine them?
if you were supplied with solutions of 1.0m HF and 1.0 NaF and asked to make 100 ml of buffer solution of ph=4.17 what quantities of the two solutions would you mix together?
4. If you want to make a buffer of 4.5 pH, how many grams of NaF do you need to add to 300 mL of 0.4 M HF solution? (Ka=7.1x10-4) Answer: 114.66 grams Pka -log (7.1 X10-4) = 3.1487411651 234
12. Which of the following mixtures would result in a buffered solution when 1.0 L of each of the two solutions are mixed? (Select all that apply.) 0.3 M HNO3 and 0.5 M NaNO 0.3 M HNO3 and 0.4 M NaOH 0.2 M HNO3 and 0.6 M HF 0.2 M HNO3 and 0.4 M NaF
§Which of the following will not produce a buffered solution? a.100 mL of 0.1 MNa2CO3and 50 mL of 0.1 MHCl b.100 mL of 0.1 MNaHCO3and 25 mL of 0.2 MHCl c.100 mL of 0.1 MNa2CO3and 75 mL of 0.2 MHCl d.50 mL of 0.2 MNa2CO3and 5 mL of 1.0 MHCl e.100 mL of 0.1 MNa2CO3and 50 mL of 0.1 MNaOH I know the answer is e, but I don't understand how the other choices are considered buffers. Aren't buffers supposed...