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Method

Half fill a beaker with boiling water and add a large test tube that is a

quarter full of ethanol. Allow the ethanol to come to the boil. Do not heat

the ethanol in a Bunsen burner flame. This is not safe because ethanol is

highly flammable.

Take a leaf that has been sitting in good light for at least a few days, and

soften on the boiling water for ten seconds or so. Then add to the ethanol

and allow to boil for about a minute until all the colour disappears from

the leaf.

Remove the leaf from the ethanol. Put it back in the hot water to soften for

10 seconds.

Spread the leaf out on a white tile and use the iodine solution to test for

starch A blue-black colour indicates starch is present.

This experiment can be repeated with leaves that have been left in the dark.

or have been deprived of carbon dioxide.

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A chemical solution used to test starch is?

the answer to tis would be iodine because it is uses in the method to test for presence of startch in a leaf


Why is it necessary to boil the ethanol tube in the water bath to test the starch in green leaf?

Boiling the ethanol tube in a water bath is necessary to remove chlorophyll from the green leaf, which can interfere with the starch test. The heat helps to break down the leaf's cellular structure, allowing the ethanol to extract pigments effectively. Once the chlorophyll is removed, the leaf can be tested for starch presence using iodine solution, which will turn blue-black in the presence of starch. This process ensures accurate results in identifying starch accumulation in the leaf.


Why is it important to bleach the leaf before the starch of pant?

Bleaching the leaf is important because it removes chlorophyll and other pigments, making it easier to test for the presence of starch. By doing so, you ensure that any color change observed during the iodine test is solely due to the presence of starch, rather than interference from other pigments. This process helps confirm that photosynthesis has occurred and that starch has been produced in the plant.


What is the discussion of testing leaves for starch?

Testing leaves for starch involves performing a chemical test to determine the presence of glucose, which is stored as starch in plants. This test typically involves applying iodine solution to the leaf, which turns blue-black in the presence of starch. This process helps to demonstrate the process of photosynthesis and the role of leaves in storing energy.


What effect does iodine have when added directly to a leaf in an experiment?

Iodine added directly to a leaf in an experiment can be used to test for the presence of starch. If the leaf turns blue-black, it indicates that starch is present in the leaf, as iodine reacts with starch molecules to produce this color change. This is commonly used in biology experiments to show the photosynthesis process in plants.

Related Questions

What is the purpose of covering the leaf with iodine?

Covering a leaf with iodine helps to test for the presence of starch. Iodine reacts with starch to produce a blue-black color, indicating the presence of this carbohydrate in the leaf. This test is commonly used in biology experiments to detect the storage of starch in plant leaves.


Why the leaf boiled in alcohol for a starch test?

The leaf is boiled in alcohol to remove the chlorophyll and other pigments that can interfere with the starch test. This process helps to showcase the presence of starch in the leaf by removing any substances that may obscure the results.


A leaf was taken from a plant boiled with ethanol and tested with iodine solution what is it tested for?

The iodine test is commonly used to detect the presence of starch in a sample. If the leaf turns blue-black when treated with iodine solution after boiling with ethanol, it indicates the presence of starch in the leaf tissue.


What is the role of iodine in testing a leaf for starch?

A hot bath of ethanol decolorizes the leaf by washing out the chlorophyll. If the leaf is not decolorized, you cannot see the blue-black stain that results from the iodine reacting with the starch.


What happened a non green leaf is tested for starch?

A non-green leaf lacking chloroplasts will not be able to synthesize food which later on gets converted into starch. So it will not show the presence of starch in the test.


A chemical solution used to test starch is?

the answer to tis would be iodine because it is uses in the method to test for presence of startch in a leaf


What happens when iodine is dropped into a leaf?

When iodine is dropped onto a leaf, it reacts with starch present in the leaf to form a blue-black color. This color change is used to test for the presence of starch in the leaf tissue. Absence of blue-black color indicates that starch is not present in the leaf.


What effect the iodine solution have on a leaf?

Iodine solution can test for the presence of starch in a leaf. When iodine solution is applied to a leaf, it will turn blue-black in areas where starch is present. This is because iodine reacts with starch to form a bluish-black complex.


Why does only half of the leaf turn blue black when tested for the presence of starch with iodine solution?

The half of the leaf that turns blue black in the iodine test for starch is the part that was exposed to light during photosynthesis. Starch is produced in the chloroplasts of plant cells as a result of photosynthesis, so the areas of the leaf that were able to photosynthesize will contain starch and react with the iodine to give a blue-black color.


Why did the leaf turn blue black when iodine was added in the starch test?

The leaf turned blue-black in the starch test because iodine forms a complex with starch molecules, resulting in the blue-black color change. This color change indicates the presence of starch in the leaf tissue.


Why is it important to bleach the leaf before the starch of pant?

Bleaching the leaf is important because it removes chlorophyll and other pigments, making it easier to test for the presence of starch. By doing so, you ensure that any color change observed during the iodine test is solely due to the presence of starch, rather than interference from other pigments. This process helps confirm that photosynthesis has occurred and that starch has been produced in the plant.


WHY WAS THE LEAF TURN WHEN IODINE SOLUTION WAS PLACE ON IT?

The leaf turned black when iodine solution was placed on it because iodine reacts with starch present in the leaf, forming a dark blue-black complex. This color change is a common test used to detect the presence of starch in a leaf.