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Titration curves and buffering capacity (with the Cobra3 Ba-sic-Unit)

Product No: P3061611

Principle

pH values can be measured with the aid of electrochemical measurements and proton-sensitive electrodes (e.g. glass electrodes). By combining a glass electrode with a reference electrode in one housing, a single-rod glass electrode, which is appropriate for acid-base titrations, is created. The titration curves allow an exact determination of the equivalence point in titrations of strong and weak acids and bases.

Tasks

Determine the titration curves of different neutralisation reactions.
Determine the titration curve of an ampholyte (glycine).
Determine the buffering capacity of various aqueous acetic acid/sodium acetate mixtures at different total concentrations.

What you can learn about

Strong and weak electrolytes
Hydrolysis
Dissociation of water
Amphoteric electrolytes
Isoelectric point
Law of mass action
Indicators
Glass electrode
Activity coefficient
Buffering capacity
Henderson-Hasselbalch equation

Materiallist (Excerpt)	Product	Amount
Set of Precision Balance Sartorius CPA 623S and measure software, 230 V	49224-88	1
Cobra3 BASIC-UNIT, USB	12150-50	1
Measuring module pH/potential	12101-00	1
Measuring module, Temperature NiCr-Ni, 330°C	12104-00	1
Immers. probe NiCr-Ni, teflon, 200°C	13615-05	1
Magnetic stirrer Mini / MST	47334-93	1
Modulconverter COBRA3-mea.unit	12150-04	1
pH-electrode, polythene sheathed	18450-00	1
Buffer solution, pH 4.62 1000 ml	30280-70	1
Buffer solution, pH 9 1000 ml	30289-70	1
Retort stand, h 750 mm	37694-00	1
Power supply 12V / 2A	12151-99	1
Burette, lateral stopcock, Schellbach, 50 ml, graduations 0, ml	36513-01	2
Burette, lateral stopcock, Schellbach, 25 ml, graduations0,05 ml	36506-01	1
Software Cobra3 pH and potential	14509-61	1
Holder for two electrodes	45284-01	1
Burette clamp, roller mount.,2pl.	37720-00	1
Caustic soda sol.,1.0M 1000 ml	48329-70	1
Hydrochloric acid, 1.0 mol/l, 1000 ml	48454-70	1
Sodium acetate, anhydr. 250 g	31612-25	1
Water, distilled 5 l	31246-81	2
Acetic acid, 1 M sol., 1000 ml	48127-70	1
Volumetric flask 1000ml, IGJ24/29	36552-00	4
Pipette dish	36589-00	1
Ortho-phosphoric acid 85% 250 ml	30190-25	1
Glycocoll /glycine/ 100 g	31341-10	1
Volumetric flask 500 ml, IGJ19/26	36551-00	1
Pipettor	36592-00	1
Volumetric flask 250 ml, IGJ14/23	36550-00	7
Pasteur pipettes, 250 pcs	36590-00	1
Spring balance holder	03065-20	1
Weighing dishes, square shape, 84 x 84 x 24 mm, 25 pcs.	45019-25	1
Right angle clamp	37697-00	1
Volumetric pipette, 50 ml	36581-00	5
Volumetric pipette, 25 ml	36580-00	5
Rubber caps, 10 pcs	39275-03	1
Glass beaker DURAN®,tall, 150 ml	36003-00	16
Glass beaker DURAN®, tall, 250 ml	36004-00	1
Glass beaker DURAN®, tall, 100 ml	36002-00	1
Glass beaker DURAN®, tall, 50 ml	36001-00	3
Funnel, glass, top dia. 80 mm	34459-00	3
Spoon, special steel	33398-00	1
Funnel, glass, top dia. 55 mm	34457-00	2
Volumetric pipette, 2 ml	36576-00	1
Magnetic stirring bar 30 mm, cylindrical	46299-02	1
Wash bottle, plastic, 500 ml	33931-00	1
Volumetric pipette, 1 ml	36575-00	1
Graduated pipette 10 ml	36600-00	1
Graduated pipette, 1 ml	36595-00	1
Laboratory Experiments Physics, Chemistry, Biology andApplied Sciences, CD-ROM, incl. operating manuals	16502-42	1