Download reagent tests of known substances

REAGENT TESTS OF KNOWN SUBSTANCES
Food Substance
Gelatin
Glucose
Starch
Sodium Chloride
Reagent Test
Results
Biuret Solution
Benedict’s Solution
Lugol’s iodine Solution
Silver nitrate Solution (1%)
Lavender
Yellow  Brown
Dark Blue/Purple
White/ cloudy
ANALYSIS OF COMPOUNDS IN COMMON FOOD
Substance
Protein
Prediction
EGG
Results
Prediction
Potato
Results
Prediction
Sauce
Results
Prediction
Carrot
Results
Prediction
Banana
Results
Prediction
Salsa
Results
Prediction
Liver
Results
Prediction
Lemon
Results
Prediction
Cranberry
Results
Prediction
Apple
Results
Prediction
Kidney Beans
Results
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-
Glucose
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Starch
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Sodium Chloride
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Antiporda 1
Angelica Antiporda
Ms. Delong
H Bio Period 9
7 November 2005
Title: Compounds of Living Things
Objective: To determine whether or not each of the following: Protein, Glucose, Starch,
Sodium Chloride are present in various food.
Hypothesis: Protein will be present in all food. Starch will be present in only Potato,
Carrot, Salsa, and Liver. Glucose will be present in Carrot, salsa, and Lemon. Sodium
Chloride will be present in all food except Cranberry, apple, and kidney beans.
Materials:
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Safety Goggles
Lap Apron
25-mL beaker
10 mL Graduated Cylinder
Test Tubes
Test-tube clamp/tong
Test-tube rack
Pipette
Pi-pump
Hot plate
Benedict’s Solution in dropping bottle
Biuret Solution in dropping bottle
Lugol’s iodine solution in dropping bottle
Silver nitrate solution (1 %) in dropping bottle
Food assigned by teacher
Procedure:
1) Safety: Put on safety goggles, lab apron and follow necessary lab safety
precautions.
2) Copy table 1B.1: Reagent tests of known Food substances. (Copy table on
projector) Fill it out according to the observations you make as the teacher
demonstrates
3) Copy Table 1B.2: Analysis of Compounds in Common Food (or the table on
projector). Fill out your prediction for each food and substance using a plus sign
(+) for present and a negative sign (-) for negative.
4) Protein test: Place 5 mL of assigned food in a test tube. Add 10 drops of Biuret
solution. Compare the results (color) to the information you have copied down on
Antiporda 2
the Reagent test of Known Food substances chart. Record the results on the
Analysis of Compounds in common food chart, using a plus or negative sign.
5) Glucose Test: Add 3 mL of Benedict’s solution to 5 mL of the assigned food.
Place test tube in a beaker of boiling water, and heat for 5 minutes. Compare the
results (color) to the information you have copied down on the Reagent test of
Known Food substances chart. Record the results on the Analysis of Compounds
in common food chart, using a plus or negative sign.
6) Starch Test: Add 5 drops of Lugol’s iodine solution to 5mL of assigned food.
Compare the results (color) to the information you have copied down on the
Reagent test of Known Food substances chart. Record the results on the Analysis
of Compounds in common food chart, using a plus or negative sign.
7) Chloride Test: Add 5 drops of silver nitrate solution to 5 mL of assigned food.
Compare the results (color) to the information you have copied down on the
Reagent test of Known Food substances chart. Record the results on the Analysis
of Compounds in common food chart, using a plus or negative sign.
8) Copy and fill out the results your other classmates got from their experiment for
the food assigned to them
9) Clean lab station.
10) Wash your hands thoroughly before living lab.
Data: see attached
Analysis:

I predicted that Protein would be present with all of the food. However, the results
in this experiment proved me wrong. For instance, according to the results Liver
does not have Protein present in it. That also goes for cranberry, carrot, lemon,
apple and Kidney beans. I had the notion that food such as apples it being a fruit
would have protein. I was rather surprised that the carrot was absent of Protein. I
predicted that Potato would be the only food that would have Starch present in it.
However, results show that the carrot, apple, and Kidney Beans have starch in
them. I was correct about my prediction that Potato would have starch in it. I
guessed that Glucose would be present in Carrot, salsa, and Lemon. I was correct
to say that Glucose would be present in Carrot and Lemon. I made a conjecture
that Sodium Chloride would be present in all food except Cranberry, apple, and
kidney beans. I was correct that Cranberry and apple would not have Sodium
Chloride present in it. I was, however, mistaken about Kidney beans not having
Sodium Chloride present for it is.
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I was correct about my prediction that the egg, potato, banana, and apple would
have positive results for Protein. My prediction that the egg and banana would not
Antiporda 3
have Glucose and that Liver, lemon, and apple would was correct. For starch I
predicted that egg, lemon, and cranberry would be negative and that potato,
carrot, and salsa would have Starch and I was also correct. I was correct to guess
that the egg, potato. Sauce, and carrot would result as positive and that Cranberry
and apple would be negative.
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According to the results listed on the chart (Analysis of Compounds in Common
Food) there was no food that contained all the compounds that were tested.
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On the basis of the tests the egg, potato, banana and apple could be used as a
source of Protein. The potato, sauce, liver, lemon, cranberry, apple, and Kidney
beans could be used as a source of Glucose. The potato, carrot, banana, salsa,
apple, and Kidney beans could be used as a source of Starch. The egg, sauce,
carrot, salsa, lemon, and kidney beans could be used as a source of Sodium
Chloride.
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I really don’t think that the original colors of the test materials could affect the
results. I do think that it may be a bit harder to determine the result because of the
hue and color scheme that the original color might affect. I think that in testing for
something like Glucose and Starch the color would make a difference, but the
results wouldn’t change because of the color range.