Freedom physics
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#1
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When light passes through a filter to the solution and then to a photoelectric cell, what happens in order for the photoelectric cell and the things after it to determine what colour the solution is? 😄
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charco
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#2
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(Original post by Freedom physics)
When light passes through a filter to the solution and then to a photoelectric cell, what happens in order for the photoelectric cell and the things after it to determine what colour the solution is? 😄
There are two beams. They both pass through a filter to remove the unwanted wavelengths.

One of the (now coloured) beams passes through the sample and the other through the reference. The instrument compares the two signals to decide what percentage of the light has been absorbed be the sample.

It makes no decision about the colour.
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Freedom physics
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Thanks but how does the first beam become colored when passed through the sample? 😄
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charco
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(Original post by Freedom physics)
Thanks but how does the first beam become colored when passed through the sample? 😄
It doesn't!
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Freedom physics
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So two beams pass through a filter and the unwanted wavelengths of light in both beams are removed, is there a change in the colour of the beams as they pass through the filter? 🙂
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Freedom physics
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Also, am I correct in saying that a filtered wavelength of light passes through the sample and some wavelengths of light pass through the sample to the photoelectric cell and the computer compares the reference beam to the wavelengths that aren't absorbed by the solution to see how much of the beam that's sent through the solution is absorbed? 😄
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Freedom physics
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#7
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Sorry about this 😂, also, what does calibration mean for a calibration curve for a graph of absorbance against concentration? And how would you measure the concentration of a substance that changes the colour of the solution it's in using a colorimeter? 😄
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