pH Meter and Measurment of Various Solutions



Hazards: HCl and NaOH are corrosive and toxic.

Chemicals and Solutions: 

Sodium carbonate, 0.1 M (basic solution)

Sodium acetate, 0.1 M (basic solution)

Ferric nitrate, 0.1 M (acid solution)

Hydrochloric acid, 0.01 M (acidic solution)

Sodium hydroxide, 0.01 M (basic solution)


pH meter

Combination pH electrode

Digital readout voltmeter and pH interface

Leads to connect pH meter, interface, and voltmeter


Polyethylene wash bottle of distilled water

6- 150 ml beakers

400 ml beaker for waste


Electrode must remain in distilled water when not in use.

After each measurement, rinse electrode with distilled water.



In the dissociation of sodium carbonate, carbonate anion reacts with water to give OH- thereby forming a basic solution:

CO32- + H2O ---> HCO3- + OH-

Similarily, in the dissociation of sodium acetate, acetate ion reacts with water to form OH-, thereby also giving a basic solution:

CH3COO- + H2O ---> CH3COOH + OH-

The hydrated ions of metals of small radius and high charge, like Fe3+ are stronger acids than water and donate protons to water molecules.  The ferric nitrate solution is acidic:

Fe(H2O)63+ + H2O ---> Fe(H2O)5(OH)2+ + H3O+

To schedule a demonstration, please send an email to the demonstration lab.



Eric Camp

Lecture Demonstration Technician

Bagley Hall 171

(206) 543-1606


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