A 350.0 mLmL buffer solution is 0.150 molL−1molL−1 in HFHF and
0.150 molL−1molL−1 in NaFNaF.
Ka(HF)=6.3×10−4
If the same volume of the buffer was 0.370 molL−1molL−1 in HFHF and 0.370 molL−1molL−1 in NaFNaF, what mass of NaOHNaOH could be handled before the pHpH rises above 4.00?
Express your answer using two significant figures.
concentration of HF = 0.150 M
concentration of NaF = 0.150 M
volume of the buffer =350 mL
Ka of HF = 6.3 x 10-4
pKa = - log Ka
= - log (6.3 x 10-4)
= 3.2
pH = pKa + log ([base] / [acid])
in the above case as base and acid are having same concentration pH = pKa
initial pH = 3.2
the number of moles of HF = 0.350 L x 0.150 mol/L
= 0.0525 mol
number of moles of NaF = 0.350 L x 0.150 mol/L
= 0.0525 mol
on adding NaOH
OH- + HF --------> F- + H2O
before reaction 0.0525 moles
addition x moles
after addition (0.0525 -x ) moles (0.0525 + x) moles
4 = 3.2 + log ((0.0525 + x) / (0.0525 -x ))
6.31 = ((0.0525 + x) / (0.0525 -x ))
x=0.0381
number of moles of NaOH is 0.0381
molar mass of NaOH = 39.996 g/mol
mass of NaOH = 0.0381 moles x 39.996 g/mol
= 1.525 g
concentration of HF = 0.370 M
concentration of NaF = 0.370 M
volume of the buffer =350 mL
Ka of HF = 6.3 x 10-4
pKa = - log Ka
= - log (6.3 x 10-4)
= 3.2
pH = pKa + log ([base] / [acid])
in the above case as base and acid are having same concentration pH = pKa
initial pH = 3.2
the number of moles of HF = 0.350 L x 0.370 mol/L
= 0.1295 mol
number of moles of NaF = 0.350 L x 0.370 mol/L
= 0.1295 mol
on adding NaOH
OH- + HF --------> F- + H2O
before reaction 0.1295 moles
addition x moles
after addition (0.1295 -x ) moles (0.1295 + x) moles
4 = 3.2 + log ((0.1295 + x) / (0.1295 -x ))
6.31 = ((0.1295 + x) / (0.1295 -x ))
x=0.0941
number of moles of NaOH is 0.0941
molar mass of NaOH = 39.996 g/mol
mass of NaOH = 0.0941 moles x 39.996 g/mol
= 3.76 g
A 350.0 mLmL buffer solution is 0.150 molL−1molL−1 in HFHF and 0.150 molL−1molL−1 in NaFNaF. Ka(HF)=6.3×10−4...
A 360.0 −mL buffer solution is 0.150 M in HF and 0.150 M in NaF. a) What mass of NaOH can this buffer neutralize before the pH rises above 4.00? = 1.6 b)If the same volume of the buffer were 0.370 M in HF and 0.370 M in NaF, what mass of NaOH could be handled before the pH rises above 4.00?
Calculate the mole ratio of NaF to HF required to create a buffer with pH=4.10. Ka(HF)=6.3×10−4 Express your answer using two significant figures. [NaF][HF] = ??
A 130.0 mL buffer solution is 0.105 molL?1 in NH3 and 0.135 molL?1 in NH4Br. 1.What mass of HCl will this buffer neutralize before the pH falls below 9.00? m=____g 2.If the same volume of the buffer were 0.270 molL?1 in NH3 and 0.400 molL?1 in NH4Br, what mass of HCl could be handled before the pH fell below 9.00? m=______g
Consider a buffer solution comprised of HF and F-. The Ka of HF is 6.3 x 10-4. If the pH of the buffer solution is 3.64 and [HF] = 0.110 M, how many moles of F- are present? The volume of the buffer solution is 297 mL.
Calculate the concentration of all species in a 0.14 M KF solution. Ka(HF)=6.3×10−4 Express your answer using two significant figures. Enter your answers numerically separated by commas.
Calculate the concentration of all species in a 0.14 M KF solution. Ka(HF)=6.3×10−4 Express your answer using two significant figures. Enter your answers numerically separated by commas. Calculate the concentration of all species in a 0.14 MKF solution. K. (HF) = 6.3 x 10 4 Express your answer using two significant figures. Enter your answers numerically separated by commas. PO ALV x x 8 O a ? x x-10 x x x = K+], F-), HF), [OH], H30+] = M...
A 130.0 −mL buffer solution is 0.100 M in NH3 and 0.135 M in NH4Br. What mass of HCl can this buffer neutralize before the pH falls below 9.00? Express the mass in grams to three significant figures. If the same volume of the buffer were 0.265 M in NH3 and 0.400 M in NH4Br, what mass of HCl could be handled before the pH falls below 9.00? Express the mass in grams to three significant figures.
A 130.0 −mL buffer solution is 0.105 M in NH3 and 0.135 M in NH4BrNH4Br. The Kb value for NH3 is 1.76×10−5 Part A What mass of HCl can this buffer neutralize before the pH falls below 9.00? Part B If the same volume of the buffer were 0.265 M in NH3 and 0.390 M in NH4Br, what mass of HCl could be handled before the pH falls below 9.00? Express the mass in grams to three significant figures.
What mass of sodium benzoate should you add to 150.0 mL of a 0.14 molL−1 benzoic acid solution to obtain a buffer with a pH of 4.25? For benzoic acid, Ka=6.3×10−5.
A 1100 ml. buffer solution is 0.110 mol L-in NH, and 0.125 mol Lin NH Br. Review Constants Periodic Table What mass of HCI will the buffer neutralize before the pH falls below 9.007(K,(NH) - 1.76 x 10-5 Express your answer using two significant figures AERO me Submit Previous Answers Request Answer X Incorrect; Try Again Part B N H, and 0.390 mol L'in NH Br, what mass of HCl could If the same volume of the buffer were 0.265...