Answer: potassium iodide is the basic test for starch,and the positive test is blue-black coloration, any other test substance which is not starch will give a negative results.
Explanation:
Starch is an example of polysaccharide and since the standard test for it is potassium iodide solution, it gives a positive test.
Diasaccharides e.g maltose are reducing sugars.their standard test is BENEDICT test .
Therefore, in the hydrolysis; starch should give a positve test, while Diasaccharides should give negative rest.
The product formed when HCl and CH2Cl2 react is CH4
H
H-C- H methane structure
H
HCl react with CH2Cl2 to form methane (CH4) and chlorine gas(Cl2)
that is,
2HCl(g) + CH2Cl2(l) = CH4 (g) +2Cl2 (g)
So the question ask to separate the reaction of the element if your problem into its component half reaction and the best answer or the elements are the following: (Cs-> Cs+ + 1e-) x2 and <span>2e-+Cl2->2Cl-. I hope you are satisfied with my answer and feel free to ask for more </span>