Dissociation constants
The coloured indicator thymol blue is a weak acid that is partially dissociated in aqueous solution, whereby non-ionized and ionized forms show absorption maximums at different wavelengths in the visible range. Photometric measurements in the visible spectral range can therefore be used to advantage to determine the position of the Ka and pKa values of the indicator which characterize dissociation equilibrium.
- Modern spectrophotometer with display
- Spectrophotometer can be used for many other applications
- Detailed operating instructions
Cell for spectrophotometer, optical glass
Ethyl alcohol, absolute 500
Thermometer -10…+50 °C
Volumetric pipette, 1 ml
Microspoon, steel
Hydrochloric acid,0.1M 1000
Pasteur pipettes, 250 pcs
Beaker, tall form, 150 ml
Buffer solution, pH 9 1000
Rubber caps, 10 pcs
Volumetric pipette, 5 ml
Wash bottle, plastic, 500 ml
Shimadzu UV-1280 Spectrophotometer 190-1100 nm
Pipettor
Volumetric flask 50 ml, IGJ12/21
Weighing dishes, square shape, 84 x 84 x 24 mm, 25 pcs.
Volumetric pipette, 10 ml
Funnel, glass, top dia. 50 mm
Graduated cylinder 250 ml
Volumetric flask 1000ml, IGJ24/29
Thymol blue indicator
Caustic soda sol.,0.1M 1000
Pipette dish
Water, distilled 5 l
- True and potential electrolytes
- Strong and weak acids
- Law of mass action
- Dissociation constants and pKa values
- Henderson-Hasselbalch- Equation
- UV-vis spectrometry
- Lambert-Beer’s Law
- Photometry