buffer solutions buffer solutions are equilibrium systems, which maintain a relatively constant ph...
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Buffer Solutions
Buffer solutions are equilibrium systems, which maintain a relatively constant pH when small amounts of acids or bases are added.
Acid Buffer Recipe
Weak Acid + Salt (conjugate)
HF NaF
Buffer Equation Same as weak acid
HF ⇋ H+ + F-
Buffer Solutions
Buffer solutions are equilibrium systems, which maintain a relatively constant pH when small amounts of acids or bases are added.
Acid Buffer Recipe
Weak Acid + Salt (conjugate)
HF NaF
Buffer Equation Same as weak acid
HF ⇋ H+ + F-
[High]
Buffer Solutions
Buffer solutions are equilibrium systems, which maintain a relatively constant pH when small amounts of acids or bases are added.
Acid Buffer Recipe
Weak Acid + Salt (conjugate)
HF NaF
Buffer Equation Same as weak acid
HF ⇋ H+ + F-
[High] [low]
Buffer Solutions
Buffer solutions are equilibrium systems, which maintain a relatively constant pH when small amounts of acids or bases are added.
Acid Buffer Recipe
Weak Acid + Salt (conjugate)
HF NaF
Buffer Equation Same as weak acid
HF ⇋ H+ + F-
[High] [low] [High]
Buffer Equation Same as weak acid
HF ⇋ H+ + F-
[High] [low] [High]
The [HF] is relatively high because HF is a weak acid and does not dissociate very much.
The [H+] is low for the same reason.
The [F-] is high due to adding the salt NaF to the solution.
This buffer solution has high concentrations of HF and F-, which means it has the ability to shift left or right and maintain the H+ concentration and hence the pH remains at a relatively constant level.
1.0 M HCN is mixed with 2.0 M NaCN to make a buffer solution.
Write the equation for the buffer solution.
Determine the [HCN] and [CN-].
HCN ⇋ H+ + CN-
1.0 M
1.0 M HCN is mixed with 2.0 M NaCN to make a buffer solution.
Write the equation for the buffer solution.
Determine the [HCN] and [CN-].
HCN ⇋ H+ + CN-
1.0 M Low
1.0 M HCN is mixed with 2.0 M NaCN to make a buffer solution.
Write the equation for the buffer solution.
Determine the [HCN] and [CN-].
HCN ⇋ H+ + CN-
1.0 M Low 2.0 M
Base Buffer Recipe
Weak Base + Salt (conjugate)
NH3 NH4Cl
Buffer Equation Same as weak base
NH3 + H2O ⇋ NH4+ + OH-
Base Buffer Recipe
Weak Base + Salt (conjugate)
NH3 NH4Cl
Buffer Equation Same as weak base
NH3 + H2O ⇋ NH4+ + OH-
[High]
Base Buffer Recipe
Weak Base + Salt (conjugate)
NH3 NH4Cl
Buffer Equation Same as weak base
NH3 + H2O ⇋ NH4+ + OH-
[High] [High]
Base Buffer Recipe
Weak Base + Salt (conjugate)
NH3 NH4Cl
Buffer Equation Same as weak base
NH3 + H2O ⇋ NH4+ + OH-
[High] [High] [Low]
Fill in the blanks to get buffer solutions. Acid Base HCN
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
NaHCO3
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
KCH3COO
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
CH3COOH KCH3COO
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
CH3COOH KCH3COO
NH4Cl
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
CH3COOH KCH3COO
NH4Cl NH3
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
CH3COOH KCH3COO
NH4Cl NH3
Na2CO3
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
CH3COOH KCH3COO
NH4Cl NH3
NaHCO3 Na2CO3
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
CH3COOH KCH3COO
NH4Cl NH3
NaHCO3 Na2CO3
NaH2PO4
Fill in the blanks to get buffer solutions. Acid Base HCN NaCN
H2CO3 NaHCO3
H3PO4 NaH2PO4
CH3COOH KCH3COO
NH4Cl NH3
NaHCO3 Na2CO3
NaH2PO4 Na2HPO4
Buffer Application
1. Pick the two buffer solutions
A. NH4Cl and HCl
B. NaCl and NaOH
C. HF and NaF
D. NH4Cl and NH3
Buffer Application
1. Pick the two buffer solutions
A. NH4Cl and HCl
B. NaCl and NaOH
C. HF and NaF
D. NH4Cl and NH3
Buffer Application
1. Pick the two buffer solutions
A. NH4Cl and HCl
B. NaCl and NaOH
C. HF and NaF
D. NH4Cl and NH3
2. Write the equations for the above two buffer solutions. Label each species in the equation as high or low concentration.
Buffer Application
1. Pick the two buffer solutions
A. NH4Cl and HCl
B. NaCl and NaOH
C. HF and NaF
D. NH4Cl and NH3
2. Write the equations for the above two buffer solutions. Label the each species in the equation as high or low concentration.
HF ⇋ H+ + F-
NH3 + H2O = NH4+ + OH-
Buffer Application
1. Pick the two buffer solutions
A. NH4Cl and HCl
B. NaCl and NaOH
C. HF and NaF
D. NH4Cl and NH3
2. Write the equations for the above two buffer solutions. Label the each species in the equation as high or low concentration.
HF ⇋ H+ + F-
[High] [Low] [High]
NH3 + H2O = NH4+ + OH-
Buffer Application
1. Pick the two buffer solutions
A. NH4Cl and HCl
B. NaCl and NaOH
C. HF and NaF
D. NH4Cl and NH3
2. Write the equations for the above two buffer solutions. Label the each species in the equation as high or low concentration.
HF ⇋ H+ + F-
[High] [Low] [High]
NH3 + H2O = NH4+ + OH-
[High] [High] [Low]
3. A few drops of 0.10 M NaOH is added to a buffer solution at pH = 5.00. The new pH could be:
A 4.98
B. 5.02
C. 8.05
D. 2.11
3. A few drops of 0.10 M NaOH is added to a buffer solution at pH = 5.00. The new pH could be:
A 4.98
B. 5.02
C. 8.05
D. 2.11
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-]
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8 Right
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8 Right Blue
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8 Right Blue [HInd] < [Ind-]
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8 Right Blue [HInd] < [Ind-]
At pH = 0.8
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8 Right Blue [HInd] < [Ind-]
At pH = 0.8 Middle
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8 Right Blue [HInd] < [Ind-]
At pH = 0.8 Middle Green
Indicators
Methyl violet HInd ⇋ H+ + Ind-
Acid Base
Yellow Blue
Shift Colour
At pH < 0.8 Left Yellow [HInd] > [Ind-] At pH > 0.8 Right Blue [HInd] < [Ind-]
At pH = 0.8 Middle Green [HInd] = [Ind-]
@ the transition point
Ka = [H+]
Ka = 10-pH
Ka = 10-0.8
= 0.2
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