AQA As Applied Science Unit 3. Colorimetry experiment on Ribena juices

by kamranbadboyhotmailcom (student)

Colorimetry

Aim:

The aim behind this science is to measure colours and to predominantly quantify the colour of light sources or objects from visual colour matches. (This means that the eye(s) are used as a tool to identify if the colour is identical or not.

Scenario: I am a scientist, my first task is to go into a laboratory and test the concentrations of different Ribena juices, then I am going to find out the unknown dilutions for both Tesco and Asda Ribenas.

Hypothesis:

The more expensive the higher quality it will be therefore the stronger the concentration of the drink. The cheaper the Ribena juice the lower quality it will be therefore a weaker concentration of the drink.

Scientific Background:

A specific solution will be used to measure and determine the absorbance of particular wavelengths of light by a specific solution.

This is the procedure is used to measure the amount of light something absorbs, this is then measured in units of absorbance, this is also directly proportional to its concentration, this method is used to determine concentration. Colorimetry is also the technology and science used to quantify and describe the human colour perception.

What is colorimetry used for?

Colorimetry is used in most industries such as:

Food
Paint manufacturing
Colour printing
Textile manufacturing
Chemistry

ASDA

Equipment:

Ribena
Distilled water
Curette
Graduated flask
Graph paper
Pipette
Colorimetric
Glass Beakers
Pipette filler

Method:

Set up all the Colorimetry equipment
Get a Pipette filler and a Pipette and measure 20ml of the Ribena
Put 20ml in to a graduated flask
Put water in until it reaches the mark
Measure the Ribena juice and the distilled water
Put a sample of pure distilled water in to the curette and set to zero
Pour the Ribena juice and distilled water in to the Graduated flask
Close the top of the volumetric flask and shake them together so that the Ribena juice and distilled water mix
Put a small amount of the solution gathered in to a curette
Record the absorbance, this is done by a number which shows up on the curette
Repeat these steps depending on the amount of Ribena
At the end plot a calibration graph with all the concentrations and percentages

Results:

Tesco

Equipment:

Ribena
Distilled water
Curette
Graduated flask
Graph paper
Pipette
Colorimetric
Glass Beakers
Pipette filler

Method:

Set up all the Colorimetry equipment
Get a Pipette filler and a Pipette and measure 20ml of the Ribena
Put 20ml in to a graduated flask
Put water in until it reaches the mark
Measure the Ribena juice and the distilled water
Put a sample of pure distilled water in to the curette and set to zero
Pour the Ribena juice and distilled water in to the Graduated flask
Close the top of the ...

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Tesco

Equipment:

Ribena
Distilled water
Curette
Graduated flask
Graph paper
Pipette
Colorimetric
Glass Beakers
Pipette filler

Method:

Set up all the Colorimetry equipment
Get a Pipette filler and a Pipette and measure 20ml of the Ribena
Put 20ml in to a graduated flask
Put water in until it reaches the mark
Measure the Ribena juice and the distilled water
Put a sample of pure distilled water in to the curette and set to zero
Pour the Ribena juice and distilled water in to the Graduated flask
Close the top of the volumetric flask and shake them together so that the Ribena juice and distilled water mix
Put a small amount of the solution gathered in to a curette
Record the absorbance, this is done by a number which shows up on the curette
Repeat these steps depending on the amount of Ribena
At the end plot a calibration graph with all the concentrations and percentages

Results:

Risk Assessment:

Conclusion:

Tesco

My dilution percentage compared to the actual was not far off that means that my test went well as I have got a similar result.

Asda:

For my Asda test I had also got similar results this means that my test went well and is correct.

Evaluation:

In my test I had followed the risk assessment and method precisely to avoid any errors. I had made sure that I had goggles on to avoid any damage happening to my eyes, I had also made sure that the methods were completely followed as if I did not follow my method completely this could affect my final results. I had also repeated both experiments twice to make sure that everything is correct and to make my results more reliable. Over all my test went well and all the results which I received were correct. I did well as I made sure that I had followed the method precisely avoiding any errors. At the end of my test I had then compared my results with my class mates and all the results were more all less the same, therefore I feel that the test which I have done is accurate and the results are precise. If I was to do my experiment again I would make sure that I prepare my self in a more efficient way as I would organise my equipment in a much better way.

Limitation:

The limitation on my colorimetry test can be that if the precise level of the amount of Ribena juice was not used as I had listed this may make my results go wrong, another limitation is if the curette was not set to zero this could be a huge impact as it could affect the results and therefore give incorrect results. Due to both Ribenas having a very similar colour if I was not organised the Ribenas could of got mixed up which would of gave me totally different results.

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