Review Questions 8NAME LAB SECTION NO DATE 1. In this exercise, which material o
ID: 216164 • Letter: R
Question
Review Questions 8NAME LAB SECTION NO DATE 1. In this exercise, which material or substance is used to test an unknown solution for the presence of sugar? 2. How is the test for sugar performed? 3. What is the equivalent test for starch? 4. What is the equivalent test for protein? 5. What is the equivalent test for oil? 6. Where, specifically, is the Sudan IV dye located in the Brazil nut slivers? 7. What property of an oil enables it to be separated from water? 8. How do you think the color of purple cabbage would be affected if the plant were grown in an acid soil?Explanation / Answer
1. Benedict's solution is used to test an unknown solution for the presence of sugar. It identifies free aldehyde or ketone groups present in the sugar molecule.
2. Following is the procedure for benedict's test:
a. Take 1 ml of sample in a clean test tube.
b. Add 10 drops of Benedict's solution to the test tube
c. Heat the solution in a boiling water bath for 3-5 minutes.
d. Observe for color change in the solution of test tubes or precipitate formation.
Observation and inference:
a. If the color upon boiling is changed into green, then there would be 0.1 to 0.5 percent sugar in solution.
b. If it changes color to yellow, then 0.5 to 1 percent sugar is present.
c. If it changes to orange, then it means that 1 to 1.5 percent sugar is present.
d. If color changes to red,then 1.5 to 2.0 percent sugar is present.
e. And if color changes to brick red,it means that more than 2 percent sugar is present in solution.
3. Equivalent test for starch is Iodine test
4. Equivalent test for protein is Bradford test.
5. Equivalent test for oils is Sudan red test
6. Sudan IV will stain specifically the nuts in the brazil nut silvers
7. Hydrophobic nature or oils enables it to be separated from water
8. Colour of cabbage will turn purple when they are grown in an acidic soil.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.