Researching pt 3 ✓ Flashcards
Colorimetric analysis
What is Colorimetry?
Colorimetry is a technique used to determine the concentration of coloured ions in solution or the concentration of ions that can be converted into coloured species
What colour filter should be used in a Colorimeter?
The colour complementary to the colour of the solution
What is a Colorimeter?
(Also known as a spectrophotometer)
A colorimeter is a piece of equipment that passes light of a complementary colour through the solution to measure the light that is absorbed or transmitted
How is the absorbance of a solution measured?
(Beer’s Law)
The difference between the intensity of incident light and the intensity of transmitted light is compared to figure out a solutions absorbance
NOTE: This is what a colorimeter does
How do you calibrate a colorimeter?
A colorimeter should be calibrated each time its used.
This is done using a ‘blank’, which is a sample of deionised water in a cuvette.
It absorbs no light so the absorbance will be set to zero, ensuring an accurate reading.
What are Optically matched cuvettes?
Optically matched cuvettes are cuvettes that have identical absorbing and scattering properties
What is a Standard (calibration) graph?
(How is it prepared?)
A standard (calibration) graph is a graph that plots absorbance against concentration. It is prepared using a colorimeter and accurately known concentrations of a known solution.
