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Testing for Iodide, I-
Sodium iodide, NaI, is the source of iodide anion for this experiment.
Reaction with bleach involves three steps. The brown color shows the presence of I3- ions.
Hypochlorite ion yields chlorine:
OCl- (aq) + Cl- (aq) + H2O
Cl2 (aq) + 2 OH-
Chlorine reacts with iodide anion:
Cl2 (aq) + 2 I- (aq)
I2 (aq) + 2 Cl- (aq)
Triiodide ion is formed:
I2 (aq) + I- (aq) I3- (aq)
Starch reacts with iodine and iodide to form a characteristic blue/black complex. A corn starch packing peanut is shown here.
Silver ion reacts with iodide to form silver iodide, AgI.
Ag+ (aq) + I- (aq) AgI (s)
Reaction of iodide with sulfuric acid produces hydrogen sulfide gas and brown triiodide solution in a series of reactions:
I- (aq) + H2SO4 (aq) HI (aq) + HSO4- (aq)
8 HI + H2SO4 (aq) H2S (g) + 4 I2 (aq) + 4 H2O
I2 (aq) + I- (aq) I3- (aq)
Again, starch is used to confirm the presence of iodine and iodide.
What else can I help you with?
What is the purpose for iodine test?
The purpose of the iodine test is to detect the presence of starch. Iodine reacts with starch molecules and forms a blue-black color, allowing for visual identification of the presence of starch in a sample.
What is the chemical used to test for the presence of starch?
The chemical used to test for the presence of starch is iodine.
Does iodine test for sugars?
Yes, the iodine test can be used to test for the presence of starch, not sugars. Iodine reacts with starch to form a blue-black color, indicating its presence. Sugars typically do not react with iodine in this way.
What is the chermical you test for starch?
Iodine solution is commonly used to test for the presence of starch. When iodine solution is added to a substance containing starch, the mixture turns blue-black in color, indicating the presence of starch.
What substance does Iodine test for?
Iodine is commonly used to test for the presence of starch. When iodine comes into contact with starch, it turns from its amber color to a blue-black color. This color change indicates the presence of starch.
What is used to test for presence of polysaccharide?
Most likely the sucrose test. what biologist use is the iodine test. Iodine is used to test for the presence of starch( a polysaccharide) any material containing starch always turn blue-black when iodine is added.
What substance is reqired to test for starch and what colour will it go?
Iodine is used to test for the presence of starch. In the presence of starch, iodine will turn from yellow-brown to a blue-black color.
What is used to test the presence of starch?
alcohol , iodine solution
What is the principle reason for the iodine test?
The principle reason for the iodine test is to detect the presence of starch. Iodine reacts with starch and forms a dark blue or black complex, allowing for easy visualization of the presence of starch in a sample.
What element turns blue when in presence of starch?
Iodine turns blue-black when in the presence of starch. This color change is a common test for the presence of starch in biological samples.
What is the iodine test used to test for?
The iodine test is used to test for the presence of starch. Iodine solution interacts with the starch molecules, causing a color change from brownish-yellow to blue or black.
Would iodine be effective if testing for the presence of lactose?
No, iodine would not be effective for testing the presence of lactose. Iodine is typically used to detect the presence of starch, not lactose. To test for lactose, you would typically use reagents like Benedict's solution or glucose test strips.
