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8/13/2019 Chemy FInal Presentaion STPM
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TITLETo determine thepercentages of vitamins C in
various type of BRANDS OFORANGE JUICES
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Abstracts
The title of this project is to determine the
percentages of vitamins C in various brands orange
juices. This is not just to ensure consumers are able
to have a healthier and safer lifestyle, but alsoallowing them to have a better understanding about
orange juices on the market
we have used the 2,6-dichlorophenolindophenol, (
DCPIP, also DPIP ) titration method. This method
requires us to measure amount of volume of various
brands of vitamin C needed to decolorize the DCPIP
solution
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Introduction and Background
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Importance of Vitamin C
Amount of vitamin C in different brands of
orange juice
Objectives
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Most important nutrient
may not be the cure for common cold
protection against immune systemdeficiencies, cardiovascular disease, prenatal
health problem, eye disease and even skin
wrinkling.
500 miligrams daily to achieve health
Vitamin C
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Process of preparation of ready-make orange
juice
Sunkist,Tesco Choice, Minutes Maid,
Tropicana Twister.
Amount of vitamin C in different
brands
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Methodology
1. Hypothesis
2. Method3. Variables
4. Apparatus
5. Materials6. Procedure
7. Results
DEFINITION: A system of methods used in a
particular area of study. In This Case, study
about howtopicresults
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Hypothesis & Method
Sunkist, brand of orange juice
contains the highest amount
of vitamin C percentage.
Quantitative Analysis.
Student during titration with a burette
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Variables
Constant Variables: Amount of 0.1% DCPIP solution used.
Manipulated Variables: Brands of orange juices.
Reponding Variables: Percentage of vitamin C among brands oforange juices.
Brands of orange juices
0.1% DCPIP Solution
Vitamin C %
Black Guy With An Oranges Facts
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Apparatus & Materials
Test Tubes
x5
Syringes x 6
Beakers x2
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0.1% ascorbic acid (vitamin C)solution (standard solution)
50ml
0.1% freshly prepared DCPIP solution (0.1 gDCPIP in 100ml distilled water)100ml
Minute Maid Tropicana Twister Sunkist
Peel Fresh
Tesco Choice
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ProcedureS
Use 1 ml-syringe to add 1.0 ml of 0.1% DCPIP in test tube.
Draw up 5.0 ml of 0.1% ascorbic acid solution into a 5 ml-syringe, and expel any air bubbles.
Place the needle end of the 5 ml syringe in the 0.1% DCPIP and add one drop of the 0.1% ascorbicacid solution to the DCPIP in the test tube. Shake the test tube gently to mix it.
Repeat step 3 until the mixture in the tube has decolorized
Record the volume of ascorbic acid used to decolourised the DCPIP.
Repeat steps (1)(5) for two times. Then calculate the average volume used.
Repeat steps (1)(4) on a range of different brand of fruit juices using 1ml of DCPIP each time. The percentage of vitamin C in each juice sample is calculated as follows:
One molecule of ascorbic acid reacts with one molecule of DCPIP, changing its colour from blue tocolourless.
Let the volume of 0.1% ascorbic acid solution that decolourise 1 ml of 0.1% DCPIP solution = X ml
Let the volume of brand of fruit juice extract that decolourise 1ml of 0.1% DCPIP solution = Y ml.
Therefore the quantity of ascorbic acid present in the Y ml of juice extract equals the quantity of
ascorbic acid present in the X ml of the 0.1% ascorbic acid solution. Therefore, the concentration of ascorbic acid in juice extract = ( ) x 0.1%
Result:
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Results
Result:
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Observations
1 2 3
4 5 FINAL
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Discussion [Problems & Solution]
1) Mixing the flask is important to ensure that the solutions have co mpletely reacted with each other. Whenadding the iodine solution, you may see a temporary color change that goes away when you swirlthe flask. The color change that is important for this experiment is the one that is not temporaryand does not go away after mixing the solutions.
2) There are a number of reasons your titration may not work. Three of the most commonproblems that can lead to a solution not changing colors in a titration are:
Using the wrong substances. Make sure that you use Lugol's DCPIP solution or anotheriodine solution sold as a DCPIP indicator (not a pure potassium iodine solution) and a true, solubleDCPIP. (If you purchased the Science uddies kit, this problem would not apply. The materials in the kitare correct for this Project Idea.) Comparing DCPIP Solution
Using incorrect concentrations. If your vitamin C standard solution is too concentrated or your DCPIP titrationsolution is too dilute, or your DCPIP indicator solution is not between 0.5 to 1.0%, it may requiremuch more than 50 mL of DCPIP solution to titrate the standard solution and/or orange juice. Themost common problem here is an overly dilute DCPIP solution; sometimes, the Lugol's DCPIP solutionsold in stores is already dilute, and you don't need to dilute it more.
Using too much orange juice. If there is a large amount of vitamin C in the orange juice that is beingtested, it may require more than 50 mL of DCPIP titration solution for it to change color. You couldtry using a smaller volume of orange juice.
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Conclusion
Different brands of orange juices have
different amount of vitamin C content or
percentages. Sunkist, brand of orange juice
contains the highest amount of vitamin Cpercentage among other brands of orange
juices.