May 7th, 2014 — Chemistry

Wireless Spectrometry: Colored Solutions

The new PASCO Wireless Spectrometer paired with our intuitive Spectrometry software now make analyzing colored solutions easier than ever!

The free software was built specifically around spectrometry - and it works in a computer or a tablet environment. The Analyze Solution tab allows students to calibrate the Spectrometer with a blank cuvette containing the solvent. Then simply insert the solution and start recording to generate an absorbance and wavelength graph!

With the full spectrum background on, it is easy for students to relate wavelength values to colors.

Students can easily switch between absorbance and transmittance for a solution. With one click, they can add an axis to compare absorbance and transmittance at the same time.

Absorbance and transmittance
With the full spectrum background on it’s easy for students to relate wavelength values to color.

Comparing additional solutions is also easy. Simply start recording another run to get started. By comparing red and blue dyes, students will be able to make the connection between the observed color of the solution, the wavelengths of the transmitted light and the wavelengths of the absorbed light.

Absorbance of Red and Blue Dyes
The red dye absorbs mostly blue-green light, while the blue dye absorbs mostly red-orange light.

Once your students understand some of the foundations of spectrometry, they can further investigate the relationships between absorbance , concentration and time. By simply selecting the analysis wavelength on the graph, it is possible to do Beer’s law and kinetics studies of their colored solution.

Analysis wavelength of blue dye
The wavelength at 626 nm was selected for the blue dye solution.

Opening the Concentration tab in the software, leads to a Beer’s lab experiment already set up for students. A calibration curve is generated is by measuring the absorbance of a set of standard colored solutions,. Students can then evaluate the concentration of an unknown sample based on the calibration curve and its absorbance.

Beer’s Law
With the Spectrometry software, you can view a live scan of the sample while collecting absorbance and concentration data.

The Kinetics tab allows students to monitor the speed of a reaction. The absorbance at the analysis wavelength can be monitored as the blue dye solution reacts with bleach (sodium hypochlorite).

The absorbance at 626 nm plotted vs time as the reaction is occurs.

By plotting functions of concentration vs time, the order of the reaction can be determined. The software easily allows the student to switch between concentration, ln(concentration) and inverse concentration to determine if the reaction is zero, first or second order.

The PASCO Wireless spectrometer is ideally suited for any tablet or computer laboratory environment. The free Spectrometry software makes it easy for student to understand fundamental spectroscopy concepts and apply them in essential and meaningful ways.

Featured Products