+
Indoor
Outdoor
+
Outdoor
Indoor
This is a newly redesigned Water-Research.net page
Page Archive

pH Buffering Systems and Solutions

Making a pH Buffer Solution

"A buffer solution is water mixed with a chemical to give it special properties in regards to pH (acidity). The chemical, known as a buffer agent, resists pH changes when exposed to acids and bases when properly mixed in a solution. This property makes it extremely useful in protecting sensitive equipment, dealing with chemical accidents, and even in balancing the internal processes of “living things." A great example of a buffered solution is your blood. It is the combination or presence of carbonic acid (H2CO3) and bicarbonate (HCO3-) in the blood that keeps the pH of the blood in the proper range (Source).

In the table below, the masses give 0.1 M concentrations of each species, when diluted to 1.0 L, so that the [acid]:[conjugate base] ratio is unity. In most cases the pH will have to be adjusted using a pH meter and the dropwise addition of either 6 M HCl or 6 M NaOH to one liter of solution until the desired pH is reached.

Acid, formula,
and mass (g)
or volume (ml)
of standard reagent
Conjugate base, formula,
and mass
Buffer pH
Phosphoric acid 85%
H3PO4
6.8 mL
Monopotassium phosphate
KH2PO4
12.8 g
2.1
Hydrochloric acid
HCl
8.6 mL
Potassium hydrogen
phthalate
KHC8H4O4
20.4 g
2.8
Citric acid
HOC(CH2CO2H)2CO2H
19.2 g
Monopotassium citrate
HOC(CH2CO2H)2CO2K
23.0 g
3.1
Methyl succinic acid
HO2CCH2CH2CO2H
11.8
Monosodium methylsuccinate
HO2CCH2CH2CO2Na
14.0
4.1
Acetic acid
CH3CO2H
glacial
5.7 mL or
Acetic acid
CH3CO2H
dilute (36%)
15.9 mL
Sodium acetate
CH3CO2Na
8.2 g
4.75
Potassium hydrogen
phthalate
KHC8H4O4
20.4 g
Sodium hydroxide
NaOH
4.0 g
4.8
Monosodium
methylsuccinate
NaO2CCH2CH(CH3)CO2H
15.3 g
Disodium methylsuccinate
NaO2CCH2CH(CH3)CO2Na
17.5 g
5.6
Monosodium citrate
HOC(CH2CO2H)2CO2Na
21.4 g
Disodium citrate
NaOC(CH2CO2H)2CO2Na
23.6 g
5.9
Disodium citrate
HOC(CH2CO2Na)2CO2H
23.6 g
Trisodium citrate
HOC(CH2CO2Na)2CO2Na
25.8 g
6.4
Monopotassium phosphate
KH2PO4
12.8 g
Dipotassium phosphate
K2HPO4
15.8 g
7.2
DL-Cysteine
HSCH2CH(NH2)CO2H
12.1 g
Sodium DL-Cysteinate
HSCH2CH(NH2)CO2Na
14.3 g
8.1
Boric acid
H2B4O7
31.4 g
Sodium Hydroxide
NaOH
4.0 g
9.1
Sodium bicarbonate
NaHCO3
8.4 g
Sodium carbonate
Na2CO3
10.6 g
10.2
Monosodium tellurate
NaHTeO4
21.6g
Disodium tellurate
Na2TeO4
23.8g
11.3
Monosodium ascorbate
NaC6H7O6
19.8g
Disodium ascorbate
Na2C6H7O6
22.0g
11.8
Dipotassium phosphate
K2HPO4
15.8 g
Tripotassium phosphate
K3PO4
19.6 g
12.7
Boric acid
H2B4O7
31.4 g
Sodium hydroxide
NaOH
12.0 g
12.7

Additional Resources

Get Tested

Level 1
Level 4

Get Treatment

Archive Page Reference
This is a newly redesigned Water-Research.net page. To reference related archived Water-Research.net page(s) click the link(s) below:
No items found.